user.js: FF76-77: 0709 disable_unc_paths can break extensions: see OP for solution [1634267 resolved 78]

Thorin: hijacking OP to post MOAR info: June 2nd 2020

This was fixed somewhat but then reared it’s ugly head again. It is fixed in FF78. If it happens to you

• set network.file.disable_unc_paths = false (hidden pref, default false)

Note: I have already added this a second time to the user.js as a hotfix-override, until after 78 lands. That way you can update the user.js, and forget about it getting reset later - it’ll just happen for you

Alternatively, and not recommended, is the pref below

• set dom.quotaManager.useDOSDevicePathSyntax = false (default true)

I assume a restart is required.

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original post

I’m using the Firefox Developer version. It auto updated from 75 beta 12 to 76 beta 2. Upon restarting the browser, I noticed all extension settings are gone and behaving incorrectly. Upon checking the browser console, I found tons of errors about extension IndexedDB with no error code associated. I attached some samples of those error messages. Upon doing binary search on what caused the issue, I narrowed it down to the network.file.disable_unc_paths = true from prefs.js, which was pulled from the user.js of this project. Since it is a hidden preference, I do not know if this is an intended change around Firefox 76 or a regression. Can any of you verify?

IndexedDB UnknownErr: ActorsParent.cpp:615
UnknownError: IndexedDB: main/anti-tracking-url-decoration getLastModified() IndexedDB:  open() The operation failed for reasons unrelated to the database itself and not covered by any other error code. Database.jsm:28:5
IndexedDB: main/hijack-blocklists getLastModified() IndexedDB:  open() The operation failed for reasons unrelated to the database itself and not covered by any other error code. Database.jsm:28
IndexedDB: main/hijack-blocklists getLastModified() IndexedDB:  open() The operation failed for reasons unrelated to the database itself and not covered by any other error code. Database.jsm:28
sendRemoveListener on closed conduit {506e023c-7f2b-40a3-8066-bc5deb40aebe}.137438953472 ConduitsChild.jsm:108
sendRemoveListener on closed conduit {7a7a4a92-a2a0-41d1-9fd7-1e92480d612d}.137438953473 ConduitsChild.jsm:108
IndexedDB UnknownErr: ActorsParent.cpp:615 2
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code.
IndexedDB UnknownErr: ActorsParent.cpp:615 2
Problem getting stored prefs for feeds.section.topstories SectionsManager.jsm:235
Problem getting stored prefs for feeds.section.highlights SectionsManager.jsm:235
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code.
Layout was forced before the page was fully loaded. If stylesheets are not yet loaded this may cause a flash of unstyled content. aboutconfig.js:452:9
[Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]"  nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)"  location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658"  data: no] L10nRegistry.jsm:658:19
IndexedDB UnknownErr: ActorsParent.cpp:615 4
undefined history-persistence.js:32:15
IndexedDB UnknownErr: ActorsParent.cpp:615 2
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code. ExtensionStorageIDB.jsm:831
Unchecked lastError value: Error: An unexpected error occurred storage-util.js:14
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code. ExtensionStorageIDB.jsm:831
IndexedDB UnknownErr: ActorsParent.cpp:615
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code. 4 ExtensionStorageIDB.jsm:831
IndexedDB UnknownErr: ActorsParent.cpp:615
2147746065 BrowserGlue.jsm:2300
IndexedDB: blocklists/ getLastModified() IndexedDB:  open() The operation failed for reasons unrelated to the database itself and not covered by any other error code. Database.jsm:28
Log warning: The log 'Services.Common.RESTRequest' is configured to use the preference 'services.common.log.logger.rest.request' - you must adjust the level by setting this preference, not by using the level setter Log.jsm:24
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code. 3 ExtensionStorageIDB.jsm:831
Unchecked lastError value: Error: An unexpected error occurred 2 storage-util.js:15
IndexedDB UnknownErr: ActorsParent.cpp:615
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code. 2 ExtensionStorageIDB.jsm:831
item is undefined common.js:941
Unchecked lastError value: Error: An unexpected error occurred common.js:940
item is undefined common.js:929
Unchecked lastError value: Error: An unexpected error occurred common.js:928
IndexedDB UnknownErr: ActorsParent.cpp:615