Firefox crashed and now does not let me load my profile
Firefox crashed and now when I open it it shows the error message: "You've launched an older version of Firefox. Using an older version of Firefox can corrupt bookmarks and browsing history already saved to an existing Firefox profile. To protect your information, create a new profile for this installation of Firefox."
The only options are to Exit or to Create a new profile. I had to create a new one just to open Firefox and try to fix it.
I logged into the Firefox account and not a single password, bookmark or anything is in my profile.
I go to about:profiles and I see both of the profiles, the new one as default, and the old one. I open the old profile by clicking on Launch profile on new browser, and I get the same error
I checked in several articles and threads like this https://www.reddit.com/r/firefox/comments/oyofoi/opting_out_of_beta_for_stable_without_requiring_a/
I cannot find compatibility.ini file anywhere. The old profile folder has about 750 MB and the new profile has 150 MB. I tried to restart without add ons and no change. I am using Windows I have not tried to update Firefox or to have a second installation. I am running 91.2.0esr (64-bit) and is up to date.
I really need to recover my bookmarks and passwords.
Wšykne wótegrona (2)
First, I should mention that Sync takes time, and data may begin to appear gradually. However, if Firefox is idle and nothing is happening after 15 minutes, you may need to transfer some files.
Since the data you are looking for is a small set, perhaps you can drop in copies of three old files to work around this. The following steps are very verbose in case random strangers come by and want to follow along.
(A) On the about:profiles page, on the Root Directory row for the old profile, click the Open Folder button to launch that folder in Windows 10's File Explorer
Resize/position that source window on the left side of the screen (we are going to copy/paste left to right). Leaving that window open, switch back to Firefox.
(B) On the about:profiles page, on the Root Directory row for your live/working profile, click the Open Folder button to launch that folder in Windows 10's File Explorer
Resize/position that destination window on the right side of the screen. Leaving that window open, switch back to Firefox.
(C) Exit Firefox using the menu (menu button > Exit, or on the menu bar, File > Exit)
After allowing time for Firefox to complete its shutdown routine, we're going to rename the working files in the live profile in case you need them later, and/or in case your windows are switched.
(D) In the destination window on the right side:
- right-click the logins.json file, click Rename, then assign a name like loginsOLD.json and press Enter or click away to complete the edit
- right-click the key4.db file, click Rename, then assign a name like key4OLD.db and press Enter or click away to complete the edit
(E) Starting in the source window on the left side, transfer the saved logins files:
- (left side) right-click logins.json, then click Copy
- (right side) right-click a blank area of the file listing in the destination window on the right side and click Paste
- (left side) right-click key4.db, then click Copy
- (right side) right-click a blank area of the file listing in the destination window on the right side and click Paste
(F) Transfer bookmark backups:
In the source window on the left:
- Double-click the bookmarkbackups folder to open it -- Firefox should display numerous files with names similar to: bookmarks-2021-10-18_1045_gibberish==.jsonlz4
- Select all of the backup files using Ctrl+A.
- Right-click any file, then click Copy
In the destination window on the right:
- Double-click the bookmarkbackups folder to open it -- probably this is empty or just has a small file for today
- Right-click a blank area of the folder and click Paste -- Windows should drop in all the files you copied in the other window
(G) Start Firefox
Firefox should automatically detect the copied-in logins files.
To restore one of those bookmark backups, use the steps in this article: Restore bookmarks from backup or move them to another computer.
Success?
Note that the current release is Firefox 93.0, so with Firefox 91 you are a few versions behind.
You can find the full installer of the current Firefox release (93.0) in all languages and all operating systems here: