I think the bookmark file and its backup are stored in the profile directory, and if that directory was deleted during your OS reinstallation, it would be lost.

That is why its a good idea to make a regular backups of such files like bookmarks and copy them somewhere else or create a Firefox account and set up sync which will let Firefox backup bookmarks on an internet server.

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page
• https://addons.mozilla.org/firefox/addon/places-maintenance/

See also:

• http://kb.mozillazine.org/Locked_or_damaged_places.sqlite
• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page or Places Maintenance can't repair the places.sqlite database then remove all places.sqlite file(s) in the Firefox profile folder to make Firefox rebuild the places.sqlite database from the most recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Avila said

I think the bookmark file and its backup are stored in the profile directory, and if that directory was deleted during your OS reinstallation, it would be lost. That is why its a good idea to make a regular backups of such files like bookmarks and copy them somewhere else or create a Firefox account and set up sync which will let Firefox backup bookmarks on an internet server.

I've got a backup. From there I copied it into the .mozilla-folder. I`m authorized to write. Could the problem depend on the combination from passwords with the kwalletmanager? here is the screenshot form the start auf firefox.

I don't want to sync with mozilla because I dont trust.

I can import the firefox-Bookmarks into qupzilla. Can this help to find a solution?

https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings

Note : Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed.

Please let us know if this solved your issue or if need further assistance.

If the places.sqlite has been locked by another application then you need to tell this application not to interfere with files in the Firefox profile folder.

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

@cor-el I don't use windows but Linux.

Sorry, I missed that.

There is still a problem, so maybe check the permissions and owner of all files in the profile folder.

• ~/.mozilla/firefox/