A few days ago, firefox started to forget bookmarks and history. This seems to happen while firefox is idle, as I cannot reproduce it on a running browser. So far, I have resorted to restoring my .mozilla files from backup each time. Here is a minimal szenario of what happens: 1. Restore .mozilla from backup 2. Open firefox 3a. Everything works, I can see my bookmarks and history, I can browse, I can close and then repopen firefox and things still work. 3b. If I instead go and get a cup of coffee and do nothing for a while, and then come back, close and reopen firefox, all my bookmarks and history is gone. The difference between 3a and 3b is reproducible. In general, the loss of information always occurs after a longer idle period, no matter what I do. I have done the following checks to track down the problem: 1. My firefox has been updated last on July 15 via standard Fedora Linux package updates, the installed version is firefox-39.0-8.fc21. This problem first started to appear a few days ago, and I was definitely able to use firefox regularly in all the time in between. The backup .mozilla is also from way before this problem first appeared. Unfortunately, .mozilla is outside of my daily backup schedule, so I cannot bisect different backups to see if they behave differently. 2. I am not using Sync, nor do I have a firefox account. 3. I have tried uninstalling all addons with no resulting difference in behavior 4. I have tried rebuilding places.sqlite following troubleshooting instructions by rm places.sqlite* after quitting firefox. The result is instant loss of bookmarks and history, even when they where visible just before exiting the program.