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Firefox Profile - Import from Backup - Works only for next start

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Hello,

I've switched to another computer and would obviously like to re-use my old firefox profile, so I backuped it.

I tried a lot of versions, delete the old Mozilla/Firefox folder and copy the whole thing over, delete all profiles, create a new one and copy the content of my old profile into the new one, etc.

The result is pretty much always the same: It works. For ONE Firefox start. All addons are there, the bookmarks are there, everything seems fine (and also works).

But... As soon as I close Firefox and start it again, the whole browser is basically dead... corrupted. It does not display anything, the single tab that is there has no text on it, all addons are gone, the menu has no entries (or it has entries, but they have no labels) and the browser does not even react to the close button but has to be killed via right click on the task bar and select "quit" there.

Btw, the same thing happens for Thunderbird, too. Restoring the old profile works for one start, two, if I'm lucky and then it's dead in the water with the same symptoms as firefox (totally empty, menus without entry labels, etc.).

Any idea what the problem here could be?

Hello, I've switched to another computer and would obviously like to re-use my old firefox profile, so I backuped it. I tried a lot of versions, delete the old Mozilla/Firefox folder and copy the whole thing over, delete all profiles, create a new one and copy the content of my old profile into the new one, etc. The result is pretty much always the same: It works. For ONE Firefox start. All addons are there, the bookmarks are there, everything '''seems ''' fine (and also works). But... As soon as I close Firefox and start it again, the whole browser is basically dead... corrupted. It does not display anything, the single tab that is there has no text on it, all addons are gone, the menu has no entries (or it has entries, but they have no labels) and the browser does not even react to the close button but has to be killed via right click on the task bar and select "quit" there. Btw, the same thing happens for Thunderbird, too. Restoring the old profile works for one start, two, if I'm lucky and then it's dead in the water with the same symptoms as firefox (totally empty, menus without entry labels, etc.). Any idea what the problem here could be?

Chosen solution

Oh, sorry, a link would have helped. This article describes what the most useful files are:

Recovering important data from an old profile

I suggest pasting one or two at a time, testing, and watching for what breaks. I would be wary of:

  • Preference files: prefs.js and (optionally) user.js
  • Extension data file: extensions.json (stores folder paths that might not exist)
  • Offline site and extension data: [profile]\storage
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All Replies (6)

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(Oh, sorry, forgot to mention that this happens on Windows 10 Pro, freshly installed)

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Firefox:

If you test without your transferred data, in a blank profile, does Firefox work repeatedly, session after session?

Assuming so, you might transfer in just a few files at a time and see whether those cause an issue. For example, places.sqlite, logins.json and key4.db on the first test.

Thunderbird:

You probably should start a different thread on the Thunderbird board:

https://support.mozilla.org/questions/new/thunderbird

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Yes, I have tried to use an freshly created profile, bookmarked example.org and restarted it quite often - always worked, never showed that "corrupted" behavior.

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Copying those three files does not seem to produce the error, but I have no clue in which order to proceed here to test which files actually does.

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Seçilmiş Həll

Oh, sorry, a link would have helped. This article describes what the most useful files are:

Recovering important data from an old profile

I suggest pasting one or two at a time, testing, and watching for what breaks. I would be wary of:

  • Preference files: prefs.js and (optionally) user.js
  • Extension data file: extensions.json (stores folder paths that might not exist)
  • Offline site and extension data: [profile]\storage
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I have now simply re-installed my extensions, seems to be stable for now. Thanks for the link, that's actually very helpful to restore some of the other stuff.

Now my main problem is Thunderbird, since actually my old mails are more important than the bookmarks for which I have a .html dump anyway. Let's hope someone can help other there, too, thanks a lot again.