hello lie,

imo, it sounds like an issue in windows that is hindering your FF.

firstly, double check to see if windows might be downloading version updates. there could be a chance, that the updating is prioritizing system resources.

secondly, be sure that the only things running in memory is your anti-virus and perhaps a graphic driver. i dont know what all you have on your system. but tweeking the startup processes would be helpful in tracking down the issues.

Thanks for the thoughts. I can find nothing wrong in Windows, and have noticed too that a brand-new profile exhibits the same problems once I have "enough" windows and tabs open. Even running only Firefox with no other user tasks hangs in the same way.

hello lie,

since you mentioned "profiles", the issue could be one involving the user profiles in windows.

i dont recall at this time if Firefox initially asks if it should install for all window users or simply installs for the current windows user. further, i dont know how FF manages user profiles as well. but this could be a possible problem in your case.

perhaps, you should consider downgrading to an older FF version that worked for you.

also, you may have a windows restore point that could restore your system back to a time when it was headache free for you.

additionally, take a look at your user accounts. if you are the only user, then you only need 1 main account and a standard default account.

It continues to be a puzzle that FF reports "Not Responding" so frequently when there is no apparent correlation between these hangs and any of the monitoring displays -- cpu, memory usage, I/O activity -- available from Task Manager. (Typing that first sentence required a great deal of time, with the now-typical hangs where keyboard entries were ignored, with a subsequent spinning cursor and the top of the screen display reading "Firefox v87.0 now .." (the name of this thread) ".. Mozilla Firefox (Not Responding)".)

"Not responding" doesn't seem to have any translation into a complaint I can attack. No hints about any constraints within Firefox itself, or in Win10.

Along with an unsuccessful experiment with a brand-new, empty profile, I have tested with all possible combinations of the Performance settings shown in the attached display: resulting in no difference in browser behavior.

I suppose as you suggest it's worth dropping back to a FF release at least two versions earlier than 87.0. Expecting that to effect a "fix" seems unreasonable, though, since these hangs began with no changes to the version I had active then, and with no obvious system or other application updates or usage patterns at the time.

It would be .. nice .. if there were a series of problem determination steps I could work through in such situations. But apparently this simply isn't the case.

One more comment here. I have a fair chunk of tabs and my hang is roughly for 10 seconds. My wife has a lot more tabs and her hangs are for something like 30 seconds.

Edit - I had another comment before this but that comment hasn't shown up. It included links to the bug database and Firefox profiles. Please tell me if I need to create the post again.

My wife and I only started getting the problem after we were upgraded automatically to v87. I have rolled back to V86.0.1 and that seems to have resolved the problem so far but it's only been a few hours and the problem is erratic. The browser starts up fine and then starts locking up after a while. Once it gets to that point it hangs every few seconds for 10 seconds at a time.

I stand corrected. The problem is now happening on V86.0.1 so rolling back didn't fix the problem.

Graymatter -- your report is nearly an echo of the symptoms I continue to see; thanks very much for taking the time to add it to the thread. I'm sorry for the problems you are seeing, but I wonder too whether these difficulties may be more widespread.

Your post is also the first entry I see from you here. If you wouldn't mind, please reply with that material again.

By the way, I understand that regressing a Firefox version will force the creation of a new profile. That action seems to mean that it is then impossible to determine whether better browser behavior is due to the older FF level, or to something amiss in the original profile.

== Just now saw your update. When you can, please confirm that you did -- or did not -- build a new profile for the fallback to v86?

My posts need moderator approval because of the links to my bug report and firefox profilers. Here is the text without the links:

I didn't build a new profile when I rolled back. I used the -allow-downgrade option to work with my old profile.

I think the links are blocking my previous post. I initially thought that the V87 upgrade was the one that caused the problem because that seemed to coinside with the freezing but that doesn't appear to be the case.

• This is happening on both my 32 bit and 64 bit version (I run both at the same time). I have only had the freeze once on the 64 bit version but I don't use that browser often.
• Firefox is freezing for about 10 seconds at a time. The whole of Firefox is unusable at this time. When it returns it continues like nothing has happened. Some things that I have noticed during the freeze is that the videos will keep playing if they are visible and the keyboard cursor keeps flashing for a bit.
• During the freezing, one of the CPU cores goes to 100% usage. This is a different core each time. The cores can switch after a very brief pause too (< 1 second)
• I have the following addons running - HTTPS Everywhere, Privacy Badger, Stylus, uBlock Origin, uBO-Scope, and uMatrix. I have used these for ages.
• I tested in safe mode but that didn't fix the problem.
• Both my wife and I are seeing the problem. In my wife's case, the freeze is for much longer (30 seconds) but she has a lot more tabs open.

Initially when I start Firefox it seems to be fine for a bit and then the hanging starts and the only way to get rid of it is to close Firefox.

It almost feels like FF is trying to look up something on the internet, perhaps a blocked/old address as quite often the problem starts when I create a new tab, type something in the address box and then press enter.

I was able to duplicate the problem without loading any tabs as follows:

I have 1 pinned tab. This normally points to gmail. I changed this tab to about:blank. I have a bunch of other tabs but they aren't loaded by default. I opened a tab at the end pointed to about:preferences and made this tab active. My firefox is set to resume the previous session so I closed firefox and opened it again. The preferences tab was visible. I left the browser for about an hour like this and worked on other stuff. I then switched back to firefox. I was able to scroll the preferences window up and down without issue which I did for about 30 seconds. I then created a new tab and the hanging immediately started. At this point I didn't even type in a URL. All I did was press Ctrl T.

Oh, boy.

Let me see if I understand your test configuration correctly: you created (or built) a Firefox session with exactly one window, and one tab in that window whose url was about:blank; you pressed Cntl-T to add a second tab, and entered about:preferences as its url; and then you restarted Firefox via a normal restart or via kiling its tasks and calling it again from its icon, or equivalent.

And at that point the result was a single window with the two tabs about:blank and about:preferences, with the latter being active. You were able to scroll and manipulate that tab without problems; but once you pressed Cntl-T once again to create a third tab and switched to it, FF was hung again?

When I have time later today I will attempt to reproduce this sequence using v87.0 after creating a brand-new profile (I assume you remain at v86 for now). For the moment I am tied up with work on another pc, but regarding this bizarre situation overall: what an odd .. mess.

I might have a fix. One of the other threads indicated that their graphics driver had been updated and that was causing their hanging. I went and checked mine (AMD) and there was a problem. The Radeon Software was saying that the graphics driver version didn't match the Radeon Software version. I am guessing that Windows decided to update the driver because I had updates disabled on the AMD side of things. I would also have expected both the Radeon software and driver to be updated if AMD was the one doing the updates. I have been running now for about an hour and a half without problems.

Edit - I spoke too soon. The problem is back :(

My test didn't only have 1 window. I have about 50 tabs open. What I did was this. I have a single pinned tab at the start (normally GMail). I changed that to about:blank. I then opened a new tab at the end and went to about:preferences. My other 50 tabs were still there but my settings say not to load tabs until I switch to them. I then closed FireFox with the preferences tab active. I reopened firefox and the preferences tab was showing. I left the browser alone for about an hour, went back to it scrolled the preferences window quite a bit, opened a new tab with Ctrl T and got the freeze immediately. None of my 50 odd tabs loaded. The freeze was immediate after I pressed Ctrl T and persisted after that until I closed Firefox.

If its your graphic driver, then you did a good job in figuring this out.

as an additional test, do you see/find any improvement if you toggle FireFox's hardware acceleration feature?

probably not, if the driver is corrupted.

but would be interesting to know though.

Graymatter -- please clarify your statement that "my settings say not to load tabs until I switch to them"? Is this different than the display I have attached with its Preferences-Tabs choosing the actions to be taken when a new tab is opened, with its checkbox empty? Thanks ..

The setting I am talking about is now the default. It's called browser.sessionstore.restore_on_demand and you can find it in about:config. Be careful changing settings there. Firefox will only load the contents of a tab when you switch to it if this setting is true. So, if you have 10 tabs open and close the browser when "Restore Previous Session" is checked, then Firefox will only load the active tab when you open the browser again, not the other 9 tabs.

@~dbben - Unfortunately the graphics driver didn't resolve the problem. I just didn't wait long enough.

I posted 2 firefox bug links and 2 firefox profile links in a previous message but this message was blocked and needed moderator approval. I think those might be helpful in resolving this problem.

Hello Grey,

It was a good try to test out the possibility regarding the graphics driver.

Let me re-read all the information that you provided us and see what all is left to do.

BTW: can you reiterate on how much ram memory you have? What is the size of your pagefile? What programs are starting up with windows when it first launches?

Also, see if maybe a windows update is having issues with downloading and installing. Sometimes window updates fail but the system continues to try installing them.

I will check back here on tomorrow.

Graymatter -- yes, I have the same (default) setting in effect for tabs. I have seen no effects either way when experimenting with the Options Performance choices, too. In fact I can often reproduce this problem by having a given tab active -- say, nytimes.com -- then killing and restarting Firefox. The browser comes back to life with that tab as the active window, and, sooner or later, activity there will hang Firefox completely for a minimum of 10 seconds per occurrence.

So far I haven't managed to see anything obviously out of bounds in Task Manager for any of the FF processes, though. The current example in the attached display never seems to indicate a value that seems way out of bounds compared to situations without obvious Firefox problems.

And for whatever it may be worth: I typed this response while the host pc was -- first -- disconnected from all WAN connections (no ISP, no gateway) and then with all connectivity disabled (WiFi turned off). Firefox continued to hang anyway -- no keyboard input accepted, spinning cursor, "Not responding" on the screen's first display line; all rather weird.

The problem was resolved for me with the latest release of Firefox.

That -- upgrade to v88.0 -- and the consequent restart did the trick for me too. No window or tab rearrangements or deletions, but with that one change all is working as it should. I have had my fingers crossed ever since, and planned to wait for a full week before reporting; but you beat me to it. The suggestion is that there was a bug in v87 and v86 at least, and it would be useful to know what that may have been, or at least an acknowledgment that there WAS a known problem. I'll settle happily just for a working level of FF, though.

Wow, lots of good detective work! I'm running the current version (92, 64-bit) and my freezes occur after I restart Win10 (from Shut Down state, nothing running), and also when I resume from Hibernation with an active session of FF at time of Hibernation.

In both instances, when the popup window "Wait or End the application" is shown, if I choose to wait, FF remains frozen. Usually the next time the window is displayed I'll choose End the application so I can carry on with what I wanted to do. Once FF has been killed and then restarted, it generally suffers no more freezing.

Although I do have, in essence, a quick-fix, I'd still like the freezes to not happen in the first place. IIRC, the freezes began after an update by FF, but I'd be surprised is Windows was completely innocent.

All suggestions welcome, thanks in advance.

R.