diff --git a/src/becca/entities/bblob.ts b/src/becca/entities/bblob.ts
index 27d559515..c37a20581 100644
--- a/src/becca/entities/bblob.ts
+++ b/src/becca/entities/bblob.ts
@@ -23,7 +23,7 @@ class BBlob {
     getPojo() {
         return {
             blobId: this.blobId,
-            content: this.content,
+            content: this.content || null,
             contentLength: this.contentLength,
             dateModified: this.dateModified,
             utcDateModified: this.utcDateModified
diff --git a/src/becca/entities/bnote.ts b/src/becca/entities/bnote.ts
index a6ae85284..26214e608 100644
--- a/src/becca/entities/bnote.ts
+++ b/src/becca/entities/bnote.ts
@@ -204,7 +204,8 @@ class BNote extends AbstractBeccaEntity<BNote> {
     }
 
     getChildBranches(): (BBranch | null)[] {
-        return this.children.map(childNote => this.becca.getBranchFromChildAndParent(childNote.noteId, this.noteId));
+        return this.children
+            .map(childNote => this.becca.getBranchFromChildAndParent(childNote.noteId, this.noteId));
     }
 
     /*
diff --git a/src/etapi/auth.js b/src/etapi/auth.js
index cdb8d5f79..835d016a1 100644
--- a/src/etapi/auth.js
+++ b/src/etapi/auth.js
@@ -1,6 +1,6 @@
 const becca = require('../becca/becca');
 const eu = require('./etapi_utils');
-const passwordEncryptionService = require('../services/encryption/password_encryption.js');
+const passwordEncryptionService = require('../services/encryption/password_encryption');
 const etapiTokenService = require('../services/etapi_tokens.js');
 
 function register(router, loginMiddleware) {
diff --git a/src/etapi/branches.js b/src/etapi/branches.js
index 6d0fa772c..e0337e5cb 100644
--- a/src/etapi/branches.js
+++ b/src/etapi/branches.js
@@ -2,7 +2,7 @@ const becca = require('../becca/becca');
 const eu = require('./etapi_utils');
 const mappers = require('./mappers.js');
 const BBranch = require('../becca/entities/bbranch');
-const entityChangesService = require('../services/entity_changes.js');
+const entityChangesService = require('../services/entity_changes');
 const v = require('./validators.js');
 
 function register(router) {
diff --git a/src/etapi/notes.js b/src/etapi/notes.js
index 0878f9d77..76318a89d 100644
--- a/src/etapi/notes.js
+++ b/src/etapi/notes.js
@@ -3,7 +3,7 @@ const utils = require('../services/utils');
 const eu = require('./etapi_utils');
 const mappers = require('./mappers.js');
 const noteService = require('../services/notes.js');
-const TaskContext = require('../services/task_context.js');
+const TaskContext = require('../services/task_context');
 const v = require('./validators.js');
 const searchService = require('../services/search/services/search.js');
 const SearchContext = require('../services/search/search_context.js');
diff --git a/src/routes/api/attributes.js b/src/routes/api/attributes.js
index 0471fc298..de906a225 100644
--- a/src/routes/api/attributes.js
+++ b/src/routes/api/attributes.js
@@ -3,7 +3,7 @@
 const sql = require('../../services/sql');
 const log = require('../../services/log');
 const attributeService = require('../../services/attributes.js');
-const BAttribute = require('../../becca/entities/battribute.js');
+const BAttribute = require('../../becca/entities/battribute');
 const becca = require('../../becca/becca');
 const ValidationError = require('../../errors/validation_error');
 
diff --git a/src/routes/api/branches.js b/src/routes/api/branches.js
index 06c81cd38..cbc951f1e 100644
--- a/src/routes/api/branches.js
+++ b/src/routes/api/branches.js
@@ -2,11 +2,11 @@
 
 const sql = require('../../services/sql');
 const utils = require('../../services/utils');
-const entityChangesService = require('../../services/entity_changes.js');
+const entityChangesService = require('../../services/entity_changes');
 const treeService = require('../../services/tree.js');
 const eraseService = require('../../services/erase.js');
 const becca = require('../../becca/becca');
-const TaskContext = require('../../services/task_context.js');
+const TaskContext = require('../../services/task_context');
 const branchService = require('../../services/branches.js');
 const log = require('../../services/log');
 const ValidationError = require('../../errors/validation_error');
diff --git a/src/routes/api/clipper.js b/src/routes/api/clipper.js
index 3992bbeda..ea4fb64c3 100644
--- a/src/routes/api/clipper.js
+++ b/src/routes/api/clipper.js
@@ -7,7 +7,7 @@ const dateNoteService = require('../../services/date_notes.js');
 const dateUtils = require('../../services/date_utils');
 const imageService = require('../../services/image.js');
 const appInfo = require('../../services/app_info.js');
-const ws = require('../../services/ws.js');
+const ws = require('../../services/ws');
 const log = require('../../services/log');
 const utils = require('../../services/utils');
 const path = require('path');
diff --git a/src/routes/api/export.js b/src/routes/api/export.js
index 3ceaaa857..440eecb8d 100644
--- a/src/routes/api/export.js
+++ b/src/routes/api/export.js
@@ -4,7 +4,7 @@ const zipExportService = require('../../services/export/zip.js');
 const singleExportService = require('../../services/export/single.js');
 const opmlExportService = require('../../services/export/opml.js');
 const becca = require('../../becca/becca');
-const TaskContext = require('../../services/task_context.js');
+const TaskContext = require('../../services/task_context');
 const log = require('../../services/log');
 const NotFoundError = require('../../errors/not_found_error');
 
diff --git a/src/routes/api/files.js b/src/routes/api/files.js
index 78fa9f5db..5e0c391d6 100644
--- a/src/routes/api/files.js
+++ b/src/routes/api/files.js
@@ -8,7 +8,7 @@ const tmp = require('tmp');
 const fs = require('fs');
 const { Readable } = require('stream');
 const chokidar = require('chokidar');
-const ws = require('../../services/ws.js');
+const ws = require('../../services/ws');
 const becca = require('../../becca/becca');
 const ValidationError = require('../../errors/validation_error');
 
diff --git a/src/routes/api/import.js b/src/routes/api/import.js
index f3fd9e28c..115546cae 100644
--- a/src/routes/api/import.js
+++ b/src/routes/api/import.js
@@ -9,7 +9,7 @@ const path = require('path');
 const becca = require('../../becca/becca');
 const beccaLoader = require('../../becca/becca_loader.js');
 const log = require('../../services/log');
-const TaskContext = require('../../services/task_context.js');
+const TaskContext = require('../../services/task_context');
 const ValidationError = require('../../errors/validation_error');
 
 async function importNotesToBranch(req) {
diff --git a/src/routes/api/login.js b/src/routes/api/login.js
index 30dc68189..7a5ff5a04 100644
--- a/src/routes/api/login.js
+++ b/src/routes/api/login.js
@@ -4,13 +4,13 @@ const options = require('../../services/options');
 const utils = require('../../services/utils');
 const dateUtils = require('../../services/date_utils');
 const instanceId = require('../../services/instance_id');
-const passwordEncryptionService = require('../../services/encryption/password_encryption.js');
+const passwordEncryptionService = require('../../services/encryption/password_encryption');
 const protectedSessionService = require('../../services/protected_session');
 const appInfo = require('../../services/app_info.js');
 const eventService = require('../../services/events');
 const sqlInit = require('../../services/sql_init.js');
 const sql = require('../../services/sql');
-const ws = require('../../services/ws.js');
+const ws = require('../../services/ws');
 const etapiTokenService = require('../../services/etapi_tokens.js');
 
 function loginSync(req) {
diff --git a/src/routes/api/notes.js b/src/routes/api/notes.js
index 810659b72..467a089f7 100644
--- a/src/routes/api/notes.js
+++ b/src/routes/api/notes.js
@@ -6,7 +6,7 @@ const treeService = require('../../services/tree.js');
 const sql = require('../../services/sql');
 const utils = require('../../services/utils');
 const log = require('../../services/log');
-const TaskContext = require('../../services/task_context.js');
+const TaskContext = require('../../services/task_context');
 const becca = require('../../becca/becca');
 const ValidationError = require('../../errors/validation_error');
 const blobService = require('../../services/blob');
diff --git a/src/routes/api/password.js b/src/routes/api/password.js
index 419a27aca..42bd8b0e0 100644
--- a/src/routes/api/password.js
+++ b/src/routes/api/password.js
@@ -1,6 +1,6 @@
 "use strict";
 
-const passwordService = require('../../services/encryption/password.js');
+const passwordService = require('../../services/encryption/password');
 const ValidationError = require('../../errors/validation_error');
 
 function changePassword(req) {
diff --git a/src/routes/api/recent_notes.js b/src/routes/api/recent_notes.js
index 5f71633bb..40139477a 100644
--- a/src/routes/api/recent_notes.js
+++ b/src/routes/api/recent_notes.js
@@ -1,6 +1,6 @@
 "use strict";
 
-const BRecentNote = require('../../becca/entities/brecent_note.js');
+const BRecentNote = require('../../becca/entities/brecent_note');
 const sql = require('../../services/sql');
 const dateUtils = require('../../services/date_utils');
 
diff --git a/src/routes/api/sender.js b/src/routes/api/sender.js
index 1e55d7a7b..000d1eecb 100644
--- a/src/routes/api/sender.js
+++ b/src/routes/api/sender.js
@@ -3,7 +3,7 @@
 const imageType = require('image-type');
 const imageService = require('../../services/image.js');
 const noteService = require('../../services/notes.js');
-const {sanitizeAttributeName} = require('../../services/sanitize_attribute_name.js');
+const {sanitizeAttributeName} = require('../../services/sanitize_attribute_name');
 const specialNotesService = require('../../services/special_notes.js');
 
 function uploadImage(req) {
diff --git a/src/routes/api/sync.js b/src/routes/api/sync.js
index aa65da91b..ab32eb671 100644
--- a/src/routes/api/sync.js
+++ b/src/routes/api/sync.js
@@ -2,7 +2,7 @@
 
 const syncService = require('../../services/sync.js');
 const syncUpdateService = require('../../services/sync_update.js');
-const entityChangesService = require('../../services/entity_changes.js');
+const entityChangesService = require('../../services/entity_changes');
 const sql = require('../../services/sql');
 const sqlInit = require('../../services/sql_init.js');
 const optionService = require('../../services/options');
@@ -10,7 +10,7 @@ const contentHashService = require('../../services/content_hash.js');
 const log = require('../../services/log');
 const syncOptions = require('../../services/sync_options.js');
 const utils = require('../../services/utils');
-const ws = require('../../services/ws.js');
+const ws = require('../../services/ws');
 
 async function testSync() {
     try {
diff --git a/src/routes/assets.js b/src/routes/assets.js
index d15201557..3f5b81013 100644
--- a/src/routes/assets.js
+++ b/src/routes/assets.js
@@ -1,7 +1,7 @@
 const assetPath = require('../services/asset_path.js');
 const path = require("path");
 const express = require("express");
-const env = require('../services/env.js');
+const env = require('../services/env');
 
 const persistentCacheStatic = (root, options) => {
     if (!env.isDev()) {
diff --git a/src/routes/index.js b/src/routes/index.js
index a7bf71e9f..277d58381 100644
--- a/src/routes/index.js
+++ b/src/routes/index.js
@@ -5,7 +5,7 @@ const attributeService = require('../services/attributes.js');
 const config = require('../services/config');
 const optionService = require('../services/options');
 const log = require('../services/log');
-const env = require('../services/env.js');
+const env = require('../services/env');
 const utils = require('../services/utils');
 const protectedSessionService = require('../services/protected_session');
 const packageJson = require('../../package.json');
diff --git a/src/routes/login.js b/src/routes/login.js
index 83ab5f87b..5aea1a6d5 100644
--- a/src/routes/login.js
+++ b/src/routes/login.js
@@ -2,9 +2,9 @@
 
 const utils = require('../services/utils');
 const optionService = require('../services/options');
-const myScryptService = require('../services/encryption/my_scrypt.js');
+const myScryptService = require('../services/encryption/my_scrypt');
 const log = require('../services/log');
-const passwordService = require('../services/encryption/password.js');
+const passwordService = require('../services/encryption/password');
 const assetPath = require('../services/asset_path.js');
 const appPath = require('../services/app_path.js');
 const ValidationError = require('../errors/validation_error');
diff --git a/src/routes/routes.js b/src/routes/routes.js
index 2bc50b359..aa67f7dba 100644
--- a/src/routes/routes.js
+++ b/src/routes/routes.js
@@ -8,11 +8,11 @@ const router = express.Router();
 const auth = require('../services/auth.js');
 const cls = require('../services/cls');
 const sql = require('../services/sql');
-const entityChangesService = require('../services/entity_changes.js');
+const entityChangesService = require('../services/entity_changes');
 const csurf = require('csurf');
 const { createPartialContentHandler } = require("express-partial-content");
 const rateLimit = require("express-rate-limit");
-const AbstractBeccaEntity = require('../becca/entities/abstract_becca_entity.js');
+const AbstractBeccaEntity = require('../becca/entities/abstract_becca_entity');
 const NotFoundError = require('../errors/not_found_error');
 const ValidationError = require('../errors/validation_error');
 
@@ -31,7 +31,7 @@ const cloningApiRoute = require('./api/cloning.js');
 const revisionsApiRoute = require('./api/revisions.js');
 const recentChangesApiRoute = require('./api/recent_changes.js');
 const optionsApiRoute = require('./api/options.js');
-const passwordApiRoute = require('./api/password.js');
+const passwordApiRoute = require('./api/password');
 const syncApiRoute = require('./api/sync.js');
 const loginApiRoute = require('./api/login.js');
 const recentNotesRoute = require('./api/recent_notes.js');
diff --git a/src/services/app_path.js b/src/services/app_path.js
index ab449495d..9f28c9fa2 100644
--- a/src/services/app_path.js
+++ b/src/services/app_path.js
@@ -1,5 +1,5 @@
 const assetPath = require('./asset_path.js');
-const env = require('./env.js');
+const env = require('./env');
 
 module.exports = env.isDev()
     ? assetPath + "/app"
diff --git a/src/services/attributes.js b/src/services/attributes.js
index a45a8ded3..685225ae7 100644
--- a/src/services/attributes.js
+++ b/src/services/attributes.js
@@ -3,7 +3,7 @@
 const searchService = require('./search/services/search.js');
 const sql = require('./sql');
 const becca = require('../becca/becca');
-const BAttribute = require('../becca/entities/battribute.js');
+const BAttribute = require('../becca/entities/battribute');
 const {formatAttrForSearch} = require('./attribute_formatter.js');
 const BUILTIN_ATTRIBUTES = require('./builtin_attributes.js');
 
diff --git a/src/services/auth.js b/src/services/auth.js
index d1a928ac2..d212f6676 100644
--- a/src/services/auth.js
+++ b/src/services/auth.js
@@ -4,9 +4,9 @@ const etapiTokenService = require('./etapi_tokens.js');
 const log = require('./log');
 const sqlInit = require('./sql_init.js');
 const utils = require('./utils');
-const passwordEncryptionService = require('./encryption/password_encryption.js');
+const passwordEncryptionService = require('./encryption/password_encryption');
 const config = require('./config');
-const passwordService = require('./encryption/password.js');
+const passwordService = require('./encryption/password');
 
 const noAuthentication = config.General && config.General.noAuthentication === true;
 
diff --git a/src/services/backend_script_api.js b/src/services/backend_script_api.js
index 58d6613dd..40e898659 100644
--- a/src/services/backend_script_api.js
+++ b/src/services/backend_script_api.js
@@ -14,12 +14,12 @@ const appInfo = require('./app_info.js');
 const searchService = require('./search/services/search.js');
 const SearchContext = require('./search/search_context.js');
 const becca = require('../becca/becca');
-const ws = require('./ws.js');
+const ws = require('./ws');
 const SpacedUpdate = require('./spaced_update.js');
 const specialNotesService = require('./special_notes.js');
 const branchService = require('./branches.js');
 const exportService = require('./export/zip.js');
-const syncMutex = require('./sync_mutex.js');
+const syncMutex = require('./sync_mutex');
 const backupService = require('./backup.js');
 const optionsService = require('./options');
 
diff --git a/src/services/backup.js b/src/services/backup.js
index 54decedcb..7fa41eb5e 100644
--- a/src/services/backup.js
+++ b/src/services/backup.js
@@ -5,7 +5,7 @@ const optionService = require('./options');
 const fs = require('fs-extra');
 const dataDir = require('./data_dir');
 const log = require('./log');
-const syncMutexService = require('./sync_mutex.js');
+const syncMutexService = require('./sync_mutex');
 const cls = require('./cls');
 const sql = require('./sql');
 const path = require('path');
diff --git a/src/services/consistency_checks.js b/src/services/consistency_checks.js
index e5ceb594f..5d9ef5104 100644
--- a/src/services/consistency_checks.js
+++ b/src/services/consistency_checks.js
@@ -3,8 +3,8 @@
 const sql = require('./sql');
 const sqlInit = require('./sql_init.js');
 const log = require('./log');
-const ws = require('./ws.js');
-const syncMutexService = require('./sync_mutex.js');
+const ws = require('./ws');
+const syncMutexService = require('./sync_mutex');
 const cls = require('./cls');
 const entityChangesService = require('./entity_changes');
 const optionsService = require('./options');
@@ -13,7 +13,7 @@ const revisionService = require('./revisions.js');
 const becca = require('../becca/becca');
 const utils = require('../services/utils');
 const eraseService = require('../services/erase.js');
-const {sanitizeAttributeName} = require('./sanitize_attribute_name.js');
+const {sanitizeAttributeName} = require('./sanitize_attribute_name');
 const noteTypes = require('../services/note_types.js').getNoteTypeNames();
 
 class ConsistencyChecks {
diff --git a/src/services/encryption/password.ts b/src/services/encryption/password.ts
index 65c6c08c0..266034d35 100644
--- a/src/services/encryption/password.ts
+++ b/src/services/encryption/password.ts
@@ -2,9 +2,9 @@
 
 import sql = require('../sql');
 import optionService = require('../options');
-import myScryptService = require('./my_scrypt.js');
+import myScryptService = require('./my_scrypt');
 import utils = require('../utils');
-import passwordEncryptionService = require('./password_encryption.js');
+import passwordEncryptionService = require('./password_encryption');
 
 function isPasswordSet() {
     return !!sql.getValue("SELECT value FROM options WHERE name = 'passwordVerificationHash'");
diff --git a/src/services/encryption/password_encryption.ts b/src/services/encryption/password_encryption.ts
index 140ae152e..36420d03d 100644
--- a/src/services/encryption/password_encryption.ts
+++ b/src/services/encryption/password_encryption.ts
@@ -1,7 +1,7 @@
 import optionService = require('../options');
-import myScryptService = require('./my_scrypt.js');
+import myScryptService = require('./my_scrypt');
 import utils = require('../utils');
-import dataEncryptionService = require('./data_encryption.js');
+import dataEncryptionService = require('./data_encryption');
 
 function verifyPassword(password: string) {
     const givenPasswordHash = utils.toBase64(myScryptService.getVerificationHash(password));
diff --git a/src/services/etapi_tokens.js b/src/services/etapi_tokens.js
index 06302ad71..1c4e0338e 100644
--- a/src/services/etapi_tokens.js
+++ b/src/services/etapi_tokens.js
@@ -1,6 +1,6 @@
 const becca = require('../becca/becca');
 const utils = require('./utils');
-const BEtapiToken = require('../becca/entities/betapi_token.js');
+const BEtapiToken = require('../becca/entities/betapi_token');
 const crypto = require("crypto");
 
 function getTokens() {
diff --git a/src/services/export/zip.js b/src/services/export/zip.js
index c5609e0d9..8fd8fd896 100644
--- a/src/services/export/zip.js
+++ b/src/services/export/zip.js
@@ -14,7 +14,7 @@ const becca = require('../../becca/becca');
 const RESOURCE_DIR = require('../../services/resource_dir').RESOURCE_DIR;
 const archiver = require('archiver');
 const log = require('../log');
-const TaskContext = require('../task_context.js');
+const TaskContext = require('../task_context');
 const ValidationError = require('../../errors/validation_error');
 const NoteMeta = require('../meta/note_meta.js');
 const AttachmentMeta = require('../meta/attachment_meta.js');
diff --git a/src/services/handlers.js b/src/services/handlers.js
index ee04b42ae..1a9c8e353 100644
--- a/src/services/handlers.js
+++ b/src/services/handlers.js
@@ -3,7 +3,7 @@ const scriptService = require('./script.js');
 const treeService = require('./tree.js');
 const noteService = require('./notes.js');
 const becca = require('../becca/becca');
-const BAttribute = require('../becca/entities/battribute.js');
+const BAttribute = require('../becca/entities/battribute');
 const hiddenSubtreeService = require('./hidden_subtree.js');
 const oneTimeTimer = require('./one_time_timer.js');
 
diff --git a/src/services/hidden_subtree.js b/src/services/hidden_subtree.js
index 0a82e61aa..6976fcab9 100644
--- a/src/services/hidden_subtree.js
+++ b/src/services/hidden_subtree.js
@@ -1,6 +1,6 @@
 const becca = require('../becca/becca');
 const noteService = require('./notes.js');
-const BAttribute = require('../becca/entities/battribute.js');
+const BAttribute = require('../becca/entities/battribute');
 const log = require('./log');
 const migrationService = require('./migration.js');
 
diff --git a/src/services/import/enex.js b/src/services/import/enex.js
index 3ef11b2ec..7cc8973ce 100644
--- a/src/services/import/enex.js
+++ b/src/services/import/enex.js
@@ -8,7 +8,7 @@ const noteService = require('../notes.js');
 const imageService = require('../image.js');
 const protectedSessionService = require('../protected_session');
 const htmlSanitizer = require('../html_sanitizer.js');
-const {sanitizeAttributeName} = require('../sanitize_attribute_name.js');
+const {sanitizeAttributeName} = require('../sanitize_attribute_name');
 
 /**
  * date format is e.g. 20181121T193703Z or 2013-04-14T16:19:00.000Z (Mac evernote, see #3496)
diff --git a/src/services/import/zip.js b/src/services/import/zip.js
index 69cbdd4bf..cf6e870ac 100644
--- a/src/services/import/zip.js
+++ b/src/services/import/zip.js
@@ -1,6 +1,6 @@
 "use strict";
 
-const BAttribute = require('../../becca/entities/battribute.js');
+const BAttribute = require('../../becca/entities/battribute');
 const utils = require('../../services/utils');
 const log = require('../../services/log');
 const noteService = require('../../services/notes.js');
@@ -13,7 +13,7 @@ const treeService = require('../tree.js');
 const yauzl = require("yauzl");
 const htmlSanitizer = require('../html_sanitizer.js');
 const becca = require('../../becca/becca');
-const BAttachment = require('../../becca/entities/battachment.js');
+const BAttachment = require('../../becca/entities/battachment');
 const markdownService = require('./markdown.js');
 
 /**
diff --git a/src/services/notes.js b/src/services/notes.js
index fa513854c..47fc0ab32 100644
--- a/src/services/notes.js
+++ b/src/services/notes.js
@@ -13,15 +13,15 @@ const path = require('path');
 const url = require('url');
 const becca = require('../becca/becca');
 const BBranch = require('../becca/entities/bbranch');
-const BNote = require('../becca/entities/bnote.js');
-const BAttribute = require('../becca/entities/battribute.js');
-const BAttachment = require('../becca/entities/battachment.js');
+const BNote = require('../becca/entities/bnote');
+const BAttribute = require('../becca/entities/battribute');
+const BAttachment = require('../becca/entities/battachment');
 const dayjs = require("dayjs");
 const htmlSanitizer = require('./html_sanitizer.js');
 const ValidationError = require('../errors/validation_error');
 const noteTypesService = require('./note_types.js');
 const fs = require("fs");
-const ws = require('./ws.js');
+const ws = require('./ws');
 const html2plaintext = require('html2plaintext')
 
 /** @param {BNote} parentNote */
diff --git a/src/services/port.js b/src/services/port.js
index cec3be8d6..c57f22a5d 100644
--- a/src/services/port.js
+++ b/src/services/port.js
@@ -1,6 +1,6 @@
 const config = require('./config');
 const utils = require('./utils');
-const env = require('./env.js');
+const env = require('./env');
 const dataDir = require('./data_dir');
 
 function parseAndValidate(portStr, source) {
diff --git a/src/services/protected_session.ts b/src/services/protected_session.ts
index 1f0e382da..6c1d6c223 100644
--- a/src/services/protected_session.ts
+++ b/src/services/protected_session.ts
@@ -66,7 +66,7 @@ function checkProtectedSessionExpiration() {
 
         log.info("Expiring protected session");
 
-        require('./ws.js').reloadFrontend("leaving protected session");
+        require('./ws').reloadFrontend("leaving protected session");
     }
 }
 
diff --git a/src/services/search/expressions/ancestor.js b/src/services/search/expressions/ancestor.js
index a3cc4bd54..5275492a1 100644
--- a/src/services/search/expressions/ancestor.js
+++ b/src/services/search/expressions/ancestor.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const log = require('../../log');
 const becca = require('../../../becca/becca');
 
diff --git a/src/services/search/expressions/attribute_exists.js b/src/services/search/expressions/attribute_exists.js
index 126f524f9..4c723a433 100644
--- a/src/services/search/expressions/attribute_exists.js
+++ b/src/services/search/expressions/attribute_exists.js
@@ -1,6 +1,6 @@
 "use strict";
 
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const becca = require('../../../becca/becca');
 const Expression = require('./expression.js');
 
diff --git a/src/services/search/expressions/child_of.js b/src/services/search/expressions/child_of.js
index d53b49c20..fde480a83 100644
--- a/src/services/search/expressions/child_of.js
+++ b/src/services/search/expressions/child_of.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 
 class ChildOfExp extends Expression {
     constructor(subExpression) {
diff --git a/src/services/search/expressions/descendant_of.js b/src/services/search/expressions/descendant_of.js
index d97dd6c62..11ad011e8 100644
--- a/src/services/search/expressions/descendant_of.js
+++ b/src/services/search/expressions/descendant_of.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const becca = require('../../../becca/becca');
 
 class DescendantOfExp extends Expression {
diff --git a/src/services/search/expressions/is_hidden.js b/src/services/search/expressions/is_hidden.js
index 32f33b512..e5ff48536 100644
--- a/src/services/search/expressions/is_hidden.js
+++ b/src/services/search/expressions/is_hidden.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 
 /**
  * Note is hidden when all its note paths start in hidden subtree (i.e., the note is not cloned into visible tree)
diff --git a/src/services/search/expressions/label_comparison.js b/src/services/search/expressions/label_comparison.js
index 01fe1396a..961bf13f5 100644
--- a/src/services/search/expressions/label_comparison.js
+++ b/src/services/search/expressions/label_comparison.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const becca = require('../../../becca/becca');
 
 class LabelComparisonExp extends Expression {
diff --git a/src/services/search/expressions/note_content_fulltext.js b/src/services/search/expressions/note_content_fulltext.js
index 0d447b7ed..6a5466a3e 100644
--- a/src/services/search/expressions/note_content_fulltext.js
+++ b/src/services/search/expressions/note_content_fulltext.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const log = require('../../log');
 const becca = require('../../../becca/becca');
 const protectedSessionService = require('../../protected_session');
diff --git a/src/services/search/expressions/note_flat_text.js b/src/services/search/expressions/note_flat_text.js
index f92c1808e..e9fc2fad8 100644
--- a/src/services/search/expressions/note_flat_text.js
+++ b/src/services/search/expressions/note_flat_text.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const becca = require('../../../becca/becca');
 const utils = require('../../utils');
 
diff --git a/src/services/search/expressions/or.js b/src/services/search/expressions/or.js
index 1704b5c60..c5a9c64c4 100644
--- a/src/services/search/expressions/or.js
+++ b/src/services/search/expressions/or.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const TrueExp = require('./true.js');
 
 class OrExp extends Expression {
diff --git a/src/services/search/expressions/order_by_and_limit.js b/src/services/search/expressions/order_by_and_limit.js
index c00f361f1..9a68f9eb2 100644
--- a/src/services/search/expressions/order_by_and_limit.js
+++ b/src/services/search/expressions/order_by_and_limit.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 
 class OrderByAndLimitExp extends Expression {
     constructor(orderDefinitions, limit) {
diff --git a/src/services/search/expressions/parent_of.js b/src/services/search/expressions/parent_of.js
index 2243d3540..5f388696b 100644
--- a/src/services/search/expressions/parent_of.js
+++ b/src/services/search/expressions/parent_of.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 
 class ParentOfExp extends Expression {
     constructor(subExpression) {
diff --git a/src/services/search/expressions/property_comparison.js b/src/services/search/expressions/property_comparison.js
index 9b014a642..5f8ac14b3 100644
--- a/src/services/search/expressions/property_comparison.js
+++ b/src/services/search/expressions/property_comparison.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const buildComparator = require('../services/build_comparator.js');
 
 /**
diff --git a/src/services/search/expressions/relation_where.js b/src/services/search/expressions/relation_where.js
index fcd0bc85c..77283b45c 100644
--- a/src/services/search/expressions/relation_where.js
+++ b/src/services/search/expressions/relation_where.js
@@ -1,7 +1,7 @@
 "use strict";
 
 const Expression = require('./expression.js');
-const NoteSet = require('../note_set.js');
+const NoteSet = require('../note_set');
 const becca = require('../../../becca/becca');
 
 class RelationWhereExp extends Expression {
diff --git a/src/services/sql.ts b/src/services/sql.ts
index 6de5003b4..ffc15a99d 100644
--- a/src/services/sql.ts
+++ b/src/services/sql.ts
@@ -248,7 +248,7 @@ function transactional<T>(func: (statement: Statement) => T) {
         const ret = (dbConnection.transaction(func) as any).deferred();
 
         if (!dbConnection.inTransaction) { // i.e. transaction was really committed (and not just savepoint released)
-            require('./ws.js').sendTransactionEntityChangesToAllClients();
+            require('./ws').sendTransactionEntityChangesToAllClients();
         }
 
         return ret;
diff --git a/src/services/sql_init.js b/src/services/sql_init.js
index 49a101cf6..da28b35d8 100644
--- a/src/services/sql_init.js
+++ b/src/services/sql_init.js
@@ -5,8 +5,8 @@ const sql = require('./sql');
 const utils = require('./utils');
 const optionService = require('./options');
 const port = require('./port.js');
-const BOption = require('../becca/entities/boption.js');
-const TaskContext = require('./task_context.js');
+const BOption = require('../becca/entities/boption');
+const TaskContext = require('./task_context');
 const migrationService = require('./migration.js');
 const cls = require('./cls');
 const config = require('./config');
@@ -62,7 +62,7 @@ async function createInitialDatabase() {
 
         require('../becca/becca_loader.js').load();
 
-        const BNote = require('../becca/entities/bnote.js');
+        const BNote = require('../becca/entities/bnote');
         const BBranch = require('../becca/entities/bbranch');
 
         log.info("Creating root note ...");
@@ -88,7 +88,7 @@ async function createInitialDatabase() {
         optionsInitService.initDocumentOptions();
         optionsInitService.initNotSyncedOptions(true, {});
         optionsInitService.initStartupOptions();
-        require('./encryption/password.js').resetPassword();
+        require('./encryption/password').resetPassword();
     });
 
     log.info("Importing demo content ...");
diff --git a/src/services/sync.js b/src/services/sync.js
index 856101703..4410e571a 100644
--- a/src/services/sync.js
+++ b/src/services/sync.js
@@ -10,10 +10,10 @@ const syncUpdateService = require('./sync_update.js');
 const contentHashService = require('./content_hash.js');
 const appInfo = require('./app_info.js');
 const syncOptions = require('./sync_options.js');
-const syncMutexService = require('./sync_mutex.js');
+const syncMutexService = require('./sync_mutex');
 const cls = require('./cls');
 const request = require('./request.js');
-const ws = require('./ws.js');
+const ws = require('./ws');
 const entityChangesService = require('./entity_changes');
 const entityConstructor = require('../becca/entity_constructor.js');
 const becca = require('../becca/becca');
diff --git a/src/services/sync_update.js b/src/services/sync_update.js
index 96922c450..6b6bbf556 100644
--- a/src/services/sync_update.js
+++ b/src/services/sync_update.js
@@ -3,7 +3,7 @@ const log = require('./log');
 const entityChangesService = require('./entity_changes');
 const eventService = require('./events');
 const entityConstructor = require('../becca/entity_constructor.js');
-const ws = require('./ws.js');
+const ws = require('./ws');
 
 function updateEntities(entityChanges, instanceId) {
     if (entityChanges.length === 0) {
diff --git a/src/services/task_context.ts b/src/services/task_context.ts
index 6aa2d9754..78ab6b10c 100644
--- a/src/services/task_context.ts
+++ b/src/services/task_context.ts
@@ -1,6 +1,6 @@
 "use strict";
 
-import ws = require('./ws.js');
+import ws = require('./ws');
 
 // taskId => TaskContext
 const taskContexts: Record<string, TaskContext> = {};
diff --git a/src/services/window.js b/src/services/window.js
index ef26ede5c..f855175c5 100644
--- a/src/services/window.js
+++ b/src/services/window.js
@@ -2,7 +2,7 @@ const path = require('path');
 const url = require("url");
 const port = require('./port.js');
 const optionService = require('./options');
-const env = require('./env.js');
+const env = require('./env');
 const log = require('./log');
 const sqlInit = require('./sql_init.js');
 const cls = require('./cls');
diff --git a/src/services/ws.ts b/src/services/ws.ts
index 64e7707c2..461b0e650 100644
--- a/src/services/ws.ts
+++ b/src/services/ws.ts
@@ -4,10 +4,10 @@ import log = require('./log');
 import sql = require('./sql');
 import cls = require('./cls');
 import config = require('./config');
-import syncMutexService = require('./sync_mutex.js');
+import syncMutexService = require('./sync_mutex');
 import protectedSessionService = require('./protected_session');
 import becca = require('../becca/becca');
-import AbstractBeccaEntity = require('../becca/entities/abstract_becca_entity.js');
+import AbstractBeccaEntity = require('../becca/entities/abstract_becca_entity');
 
 import env = require('./env');
 import { IncomingMessage, Server } from 'http';
@@ -157,7 +157,9 @@ function fillInAdditionalProperties(entityChange: EntityChange) {
 
         if (parentNote) {
             for (const childBranch of parentNote.getChildBranches()) {
-                entityChange.positions[childBranch.branchId] = childBranch.notePosition;
+                if (childBranch && childBranch.branchId) {
+                    entityChange.positions[childBranch.branchId] = childBranch.notePosition;
+                }
             }
         }
     } else if (entityChange.entityName === 'options') {