Do you recall what Firefox was doing when these crashes occurred? The latest crash is associated with a recent bug report where the speculation is that it could result from a problem playing a video. I don't know whether that is relevant in your case, and the other two are "out of memory" issues that probably aren't related to video.

Could you test in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

The last crash was when I was trying to play a YouTube video whilst typing this question but it crashed. I will try safe mode now.

This is the latest crash with safe mode: bp-1ac74bd0-8b63-4ec8-bbaf-f3ea02150731

Thank you for testing in Safe Mode.

Unfortunately, this latest report for another kind of out-of-memory crash (OOM | unknown | js::CrashAtUnhandlableOOM(char const*) | js::Nursery::moveToTenured(js::gc::MinorCollectionTracer*, JSObject*)) is a known problem that the developers have not yet been able to track down to a specific cause. According to the entry in the bug tracking system that is linked to your crash report, it seems to be particularly associated with Facebook, which has those endless pages. I don't have enough information to suggest a workaround.

jscher2000 said

Thank you for testing in Safe Mode. Unfortunately, this latest report for another kind of out-of-memory crash (OOM | unknown | js::CrashAtUnhandlableOOM(char const*) | js::Nursery::moveToTenured(js::gc::MinorCollectionTracer*, JSObject*)) is a known problem that the developers have not yet been able to track down to a specific cause. According to the entry in the bug tracking system that is linked to your crash report, it seems to be particularly associated with Facebook, which has those endless pages. I don't have enough information to suggest a workaround.

Ah yes it does on Facebook, I assume I am not the only one with this issue, I believe this hasn't happened on previous versions of FireFox until recently I've updated to this 39.0. About this OOM crash, do I have to wait until the next update for it to be fixed?