Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Thanks Fred. I tried Safe Mode, and when I run Firefox that way I can't make it lock up my system, and when I go back to running it in normal mode I still have the problem. What's puzzling is that the only extension that's installed is one for Adobe Acrobat, and while that is inactivated in Safe Mode I didn't have it activated in normal mode either. So there's something else that's different about running in Safe Mode that's not readily apparent that is inactivating something else. The only thing I can think of are the browser protection modes of Norton Internet Security and Malwarebytes, both of which I have installed (I did not install the Norton extensions for Firefox that actually run in the browser). So I'm wondering if I should try deactivating those features, although turning off browser protection isn't something that's a good idea in of itself for all the usual reasons.

Some other things that are different in Firefox's Safe Mode:

(1) Hardware acceleration of graphics is disabled

This article describes where to make that change: Firefox's performance settings. This will take effect the next time you exit Firefox and start it up again. Any difference?

Since hardware acceleration improves the appearance of fonts and animations, you may want to check whether graphics card/chipset driver updates are available for your system. This article suggests safe ways to do that: Upgrade your graphics drivers to use hardware acceleration and WebGL.

(2) JavaScript compilers are disabled (this could be an issue with some sites)

(3) userChrome.css and userContent.css are disabled (this is not likely to be very relevant)

Thanks. I updated my graphics card driver a couple of days ago, and that didn't change the situation, -the crash kept occurring when I wasn't running Firefox in safe mode. Apparently running in Safe Mode to some extent disables some aspects of the web protection modules of either Norton Internet Security and Malwarebytes, -even if those things are switched on in the settings for both programs. On a hunch I disabled Malwarebytes but left Norton enabled, then restarted Firefox in normal, not safe mode. So far, no lockups, no crashes. I have to play around with that a bit more. According to Norton it sometimes "stops" Malwarebytes from doing certain things, even though both those programs are supposed to "play nice" with each other. I set up Norton so that it won't stomp on the Malwarebytes service, and now I need to reactivate the Malwarebytes web protection to see if that made a difference. Stay tuned.

Be sure to tell both of them about the issues.

I've done a bit more experimenting, and I think I've narrowed it down to an issue with Malwarebytes' (rather aggressive) web protection feature and having tracker blocking enabled in Firefox. I disabled tracker blocking and turned Malwarebytes' web protection back on, and I haven't seen Firefox crash itself or Windows even though I've pretty much tried doing everything in Firefox that should have made it crash.

The question now is, -is this considered a Firefox issue, a Malwarebytes issue, or both?

That was very good work. Well done. Please flag your last post as Solved Problem so others will know.

A number of users have reported issues with Malwarebytes. Check with their support.

ArthurS said

I've done a bit more experimenting, and I think I've narrowed it down to an issue with Malwarebytes' (rather aggressive) web protection feature...

I had the MalwareBytes Extension some time ago and got rid of it. Too much a hassle with it.

~Pj