Strange Firefox behavior - locking up

I have Firefox 52.6 running on Win XP. For the past month or so it does this:

After the browser has been open for some random time between 5 minutes and maybe 20 minutes, it locks up. Nothing moves for about 20 seconds. I can’t switch to another program. Pages that are downloading stop. The cursor moves but doesn’t work. Then it briefly returns to operation for a few seconds then locks up again for a shorter time less then 10 seconds. Then it is OK. I have never seen it do this twice, even if I am using Firefox for hours unless I close it and open another session.

I have scanned numerous times with Malwarebytes. When it is locked up I can still ctrl-alt-delete to bring up the Task Manager and can find nothing out of the ordinary.


Did you turn off all plug-ins and add-ons? Clear your cache?

I have experienced the same. With a handful of tabs open (5 or 6) if I walk away from the computer for maybe 15 to 20 minutes when I come back the computer is sluggish to the point of being non-responsive. Even opening up task manager takes several minutes, but when I do, Firefox is using about 95% of system memory. Killing Firefox from task manager fixes the problem. Seems to happen more when I have tabs open on sites that refresh often. My solution is to use Chrome instead. I like Firefox, but damn it seems to be getting worse, not better.

My immediate impulse is to lay the blame on a very old XP which, I am certain, is not supported any longer. Dag, however, said he has the same problem. I wonder what he’s running.

Windows 10, and a decent but not cutting edge desktop machine. Core i5 ivybridge, 8 GB memory. Shouldn’t be bogged down by 6 open tabs, but yet it is with Firefox (58.0.2 64 bit) left open for a decent amount of time. The tabs that refresh frequently seem to be the culprit.

Problems like this with Firefox are often owing to a corrupted profile. You can refresh Firefox, resetting addons and settings.

FF just quit running on mine too a few months ago. Just opens a blank page and that’s it. I think the Fox isn’t feeling well. Will try anything. Legal.

I gave up on Firefox a long time ago for being slow and buggy. Went to Chrome and never looked back.

Update: I found the problem.

This freezing kept getting worse. The screen would lock for a minute or so at random intervals from a half hour to several hours. The only add on I have is Adblock. I disabled it and it seemed to work but I could not be sure as the freezing might not have occurred anyway in the time I had Adblock turned off.

After one very long freeze I looked through the settings for Adblock and in the advanced settings you can see what lists you have subscribed. Aha! A list called ABP something had just refreshed. I deleted that list and that seems to have done it.

Everything about Adblock is slow. If I go into the settings and delete a white-listed site, it takes 10 seconds for every one I delete. If I disable Adblock on a web site it takes 10-15 seconds for the Adblcok icon to turn gray.

I have removed it and re-installed it to no avail. But at least it no longer freezes the whole computer right when I am using it.


I just want to thank **mixdenny **for actually coming back and telling us the solution to their problem. It’s frustrating when I go searching the internet for solutions to a problem, appear to find a thread with a person that has a problem that matches my own, but in the end no solution is given. Or worse, they pop back in to say “Problem solved, thanks.” but don’t say what the solution was! So I applaud you taking the time to come back and post the solution so that anyone else searching the net and finding your thread has a troubleshooting method to try.

That sounds like you’re using Adblock Plus. I would suggest switching to uBlock Origin, which was specifically designed to use fewer resources than Adblock Plus.

After you install uBlock Origin, be sure to disable Adblock Plus (or any other adblock). I’d also recommend restarting after that.

It’s surprising to me, but uBlock Origin still supports Firefox 52 (that last version for Windows XP) for now, so I’d get it while it’s easy to do so.

Also, make sure you’re on 52.9.0, the last version of Firefox for Windows XP.

If the developer keeps up with releases, you may want to consider switching to a Firefox double fork called Mypal. Or, to be even safer, consider checking out a Linux distro–they all tend to let you try before you install.

Why should we have to turn off or uninstall all of our plug-ins and extensions? Isn’t there a way that extensions can be tested thoroughly enough that the chances of any mishaps would be remote?

I gave up on Firefox months ago and went to MS Edge; not that I’m sure it’s much better.

I just might try Opera again, if it’ll support my password manager.

I don’t use AdBlock Plus anymore as it was causing loads of RAM problems. I use uBlock Origin now.

Because plugins and extensions are created by random third parties who have no control over what goes on with the browser itself, and unless they’re paying close attention, are not going to know when a change in Firefox code affects their extension.

Do you expect Joe Shoesalesman who rolled up his sleeves and wrote an extension one day to test his extension every day and make immediate changes when it starts to misbehave with the latest Firefox updates? And then push the edits to you?

That’s just not how the extensions feature works.

ETA: Microsoft Edge keeps logging me out of everything, so, back to Firefox until I find something better.

Well, OK, I take your point. I can understand how an extension might overtax the resources of my computer. But I consider it completely unacceptable that the basic functionality of the browser itself is seriously compromised. Most inline links will not open at all, and none of them will open in a new tab. The only way I can open links is to copy the link location and then paste it into a new tab or window that I have manually opened. Why can’t Mozilla make Firefox sufficiently robust to prevent this sort of thing?

It’s a give and take. Mozilla gives developers the ability to access a lot of the browser’s functionality and in turn they are able to do a lot of cool stuff to customize the browsing experience. You agree to take the risk on making the browser do something it wasn’t meant to do out of the box by choosing to install extensions.

I’m not saying that an extension has borked your browser. But the very first thing to do any time Firefox starts going sideways is to turn off all your extensions and see if that helps. If it does, you can turn them back on one at a time to see if you can find the culprit.

I took this advice and switched to uBlock Origin and now I am much happier. Every site I go to seems to load faster as a benefit.