Every night Firefox crashes without any crash report. All I get is the Windows dialog that says "Firefox has stopped working" "A problem caused the program to stop working correctly. Please close the program." "Close the program". (If I can upload the screenshot I will). The websites I was on are intranet only sites, require NO Flash or Java. Two tabs only. The same sites were not crashing in much older versions, appx 6+ months ago. The only criteria for crashes seems to be the uptime of Firefox. The longer I leave it, the greater the chances of this crash. I have never seen it crash in front of my eyes, always (90%) would have crashed when I unlock the PC in the morning. I leave it running and locked the whole night. Just a couple of days ago I decided to do a complete clean install of Firefox, i.e.: Uninstall, Delete Program Files, Delete Profile folder. Reinstall, import bookmarks. That's it. Hardware Acceleration has been disabled. Provide Telemetry has been enabled. Crash Reporter is enabled, but doesn't kick in. about:crashes is empty. (Even before re-install there were no recent crashes recorded there).