Right after a disk defragmentation, my colleague suddenly had an error message in Firefox “The bookmarks and history system will not be functional because one of Firefox’s files is in use by another application. Some security software can cause this problem” and all history and bookmarks were gone.
You can use the “Learn More” button to go to the page The bookmarks and history system will not be functional to find solutions:
- Solution 1: Restart your computer
- Solution 2: Create a new places database by renaming places.sqlite
Unfortunately none of those solutions worked for us.
But we fixed it by following Solution 2 and deleting some extra files (in green) as follows:
- At the top of the Firefox window, click on the Firefox button, go over to the Help menu (on Windows XP, click on the Help menu) and select Troubleshooting Information. The Troubleshooting Information tab will open. Under the Application Basics section, click on Open Containing Folder. A window with your profile files will open.
- Exit Firefox
- In the Firefox profile folder, find and rename the files places.sqlite, places.sqlite-shm, places.sqlite-wal and places.sqlite-journal(if it exists) by adding .old at the end of their name.
- Finally, reopen Firefox. When Firefox reopens it will create a new places database. Your browsing history will be lost but Firefox will automatically import your bookmarks from the most recent backup file.