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Very high CPU usage when closing Fx 112.0.2

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  • Viimati vastas atria

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After upgrading one machine from Fx 110.0.1 to Fx 112.0.1 (as per usual with "major" upgrades with the full install file) I noticed very high CPU usage when closing Fx, and it took quite some time to settle. I upgraded it to 112.0.2 via Help-About, but saw the same issue.

That is, starting Fx, opening a "private browsing window" and visit some site, say a search engine, then closing the private window and finally the first Fx window. (At the time I also see some spikes in CPU usage from the firewall software etc.)

Since I can’t have it like this, computer almost stalling for 30 sec, after closing Fx, and to see if there would be any update later to solve this issue, I uninstalled Fx 112.0.2 (I have complete backups of Fx profiles), and, just as a test, reinstalled Fx using the prior version of setup that I had, Fx 110.0.

Of course this meant a clean profile, not what any user wants to see (missing bookmarks is almost minor compared to all settings, incl. in add-ons, gathered over time. So I used the profile manager to change to my previously used default profile. After a restart I was greeted with a prompt that this couldn’t be done (since it may corrupt bookmarks(?) etc.) and I was left with the only options to abort (cancel) or create a new profile. Oh, great. I had not even used the newer ver. (Fx 112) to change or create anything, but I assume Mozilla could have something between the different versions.

So, I uninstalled Fx 110.0 (and of course in the process of creating a new profile/resetting settings it had reverted to "download updates in background", and I had to change that setting back, and stopped what was pending, during my tests trying to move it to my old profile). I installed Fx again, using the setup file for 112.0.1 and did a direct upgrade to 112.0.2, and pointed it to my old default profile, which had been used with 110.0.1 and during the first upgrade to 112.0.1.

Fx is working with my profile again, but it takes a very long time to close and (perhaps together with other software) consumes a lot of CPU, almost stalling the PC. During one such situation this morning I got two prompts for XULRunner "Could not determine any profile running in background task mode!" Never seen before. (I noticed that there now is a new folder in Roaming\Mozilla\Firefox\ called "Background Tasks Profiles".

Any help would be very much appreciated.

After upgrading one machine from Fx 110.0.1 to Fx 112.0.1 (as per usual with "major" upgrades with the full install file) I noticed very high CPU usage when closing Fx, and it took quite some time to settle. I upgraded it to 112.0.2 via Help-About, but saw the same issue. That is, starting Fx, opening a "private browsing window" and visit some site, say a search engine, then closing the private window and finally the first Fx window. (At the time I also see some spikes in CPU usage from the firewall software etc.) Since I can’t have it like this, computer almost stalling for 30 sec, after closing Fx, and to see if there would be any update later to solve this issue, I uninstalled Fx 112.0.2 (I have complete backups of Fx profiles), and, just as a test, reinstalled Fx using the prior version of setup that I had, Fx 110.0. Of course this meant a clean profile, not what any user wants to see (missing bookmarks is almost minor compared to all settings, incl. in add-ons, gathered over time. So I used the profile manager to change to my previously used default profile. After a restart I was greeted with a prompt that this couldn’t be done (since it may corrupt bookmarks(?) etc.) and I was left with the only options to abort (cancel) or create a new profile. Oh, great. I had not even used the newer ver. (Fx 112) to change or create anything, but I assume Mozilla could have something between the different versions. So, I uninstalled Fx 110.0 (and of course in the process of creating a new profile/resetting settings it had reverted to "download updates in background", and I had to change that setting back, and stopped what was pending, during my tests trying to move it to my old profile). I installed Fx again, using the setup file for 112.0.1 and did a direct upgrade to 112.0.2, and pointed it to my old default profile, which had been used with 110.0.1 and during the first upgrade to 112.0.1. Fx is working with my profile again, but it takes a very long time to close and (perhaps together with other software) consumes a lot of CPU, almost stalling the PC. During one such situation this morning I got two prompts for XULRunner "Could not determine any profile running in background task mode!" Never seen before. (I noticed that there now is a new folder in Roaming\Mozilla\Firefox\ called "Background Tasks Profiles". Any help would be very much appreciated.

All Replies (2)

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It seems Fx is opening several processes (instead of closing) when I close the last Fx window; Task Manager shows the number of processes running increasing from, say, 80-85, to over 300! There is not much one can do while a computer is almost freezing, but if I check with for example TCPView I can see (as much as an almost stalling system allows) it closing connections and opening new ones (as could be seen in Task Manager). But they are all local.

So what is going on, and what has changed between versions 110-111-112 that can have this drastic effect?

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Solved with Fx 113. (Last resort, since no help here, would have been a new clean install and export of parts of my Fx profile to a new one, as a test. But then you'll have to track down just about everything; it's not only bookmarks & cookie settings...)

atria said

After upgrading one machine from Fx 110.0.1 to Fx 112.0.1 (as per usual with "major" upgrades with the full install file) I noticed very high CPU usage when closing Fx, and it took quite some time to settle. I upgraded it to 112.0.2 via Help-About, but saw the same issue. That is, starting Fx, opening a "private browsing window" and visit some site, say a search engine, then closing the private window and finally the first Fx window. (At the time I also see some spikes in CPU usage from the firewall software etc.) Since I can’t have it like this, computer almost stalling for 30 sec, after closing Fx, and to see if there would be any update later to solve this issue, I uninstalled Fx 112.0.2 (I have complete backups of Fx profiles), and, just as a test, reinstalled Fx using the prior version of setup that I had, Fx 110.0. [...] Any help would be very much appreciated.