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I can't migrate my Firefox profile between different Linux installations

  • 6 replies
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  • Last reply by YAFU

YAFU
YAFU
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I have been a Linux and Firefox user for many years. Whenever I wanted to migrate my profile to a new Linux installation, all I had to do was copy the contents of the old Linux installation profile folder to the new Linux installation profile folder (No matter that they had different names). Now I am trying to do it from Kubuntu 18.04 (Firefox 73.0 from PPA) to Kubuntu 20.04 (Firefox 73.0). I am doing what is explained in this guide: https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

But after doing that when I start Firefox in Kubuntu 20.04, a message appears warning that my profile data may get corrupted and therefore to protect my data it gives me only two options, starting Firefox with a new empty profile or quit firefox. So I am not able to perform the migration. How can I migrate my old profile in ofline mode? I don't want anything that requires having an account or uploading my data to some cloud thing (which I think what that Sync thing is). That is, I want to do the migration in offline mode, locally, on my machine. Thank you.

I have been a Linux and Firefox user for many years. Whenever I wanted to migrate my profile to a new Linux installation, all I had to do was copy the contents of the old Linux installation profile folder to the new Linux installation profile folder (No matter that they had different names). Now I am trying to do it from Kubuntu 18.04 (Firefox 73.0 from PPA) to Kubuntu 20.04 (Firefox 73.0). I am doing what is explained in this guide: https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles But after doing that when I start Firefox in Kubuntu 20.04, a message appears warning that my profile data may get corrupted and therefore to protect my data it gives me only two options, starting Firefox with a new empty profile or quit firefox. So I am not able to perform the migration. How can I migrate my old profile in ofline mode? I don't want anything that requires having an account or uploading my data to some cloud thing (which I think what that Sync thing is). That is, I want to do the migration in offline mode, locally, on my machine. Thank you.

All Replies (4)

YAFU
YAFU Question owner
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I have both Kubuntu 18.04 and 20.04 installations in different partitions, therefore both are perfectly functional and I can debug Firefox and content in any of the two Kubuntu installations when required. It happens that my intention is to migrate to Kubuntu 20.04 and that is why I need my old Firefox profile. It is really an old installation, with some about:config tuning of some options. So it will be tedious if I have to configure everything again from scratch. That is, Firefox works perfectly in Kubuntu 18.04 anyway in this old installation. This is the profile folder tree in old installation: 

ls -d */

bookmarkbackups/ crashes/ features/ mediacapabilities/ sessionstore-backups/ browser-extension-data/ datareporting/ gmp/ minidumps/ storage/ chrome/ extensions/ gmp-gmpopenh264/ saved-telemetry-pings/ weave/

YAFU
YAFU Question owner
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To copy the files I directly navigate the partitions from Dolphin file browser. Anyway I have done what you suggested packaging and checking the checksum, and I still get the same message when I open Firefox in Kubuntu 20.04 new installation: http://pasteall.org/pic/show.php?id=185eb9c725850701b87bb3250f4ca564

But I found that a backup of the Firefox profile in Kubuntu 18.04 that I had done about 7 months ago is working correctly when I copy the content to Firefox profile backup in Kubuntu 20.04. So the problem is something related to current data of the current profile that I am using in Kubuntu 18.04. The backup that is working is not as outdated with respect to the current profile, and I could use that one. Anyway I would like to debug and analyze the problem about why I cannot migrate with current up to date profile.

cor-el
cor-el
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You can delete compatibility.ini in that profile to prevent this profile message from being displayed.

Note that it isn't recommended to migrate a full profile because files like pkcs11.txt contain absolute paths and files like prefs.js can also store configuration data that is profile dependent.

YAFU
YAFU Question owner
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Hi That doesn't help either. Now the Firefox message does not appear, but Firefox does not start. If I launch Firefox from the terminal it does not show error messages. But I think I could solve the problem. In old profile there is a file called "addonStartup.json.lz4". I delete that file in the new installation profile. The first time I start Firefox now it starts without the addons, a new "addonStartup.json.lz4" file has been created. I close Firefox and open it again. This time the addons seem to be there and I can use my old profile. What does the "addonStartup.json.lz4" file do and what problems could I have because having removed it?

Modified by YAFU