Firefox 136.0.3 is ridiculously slow even in Safe Mode

[Graham_M]

Earlier today I upgraded to Firefox 136.0.3 64 bit with Windows 10 and now, even in Safe Mode, it's extremely slow to load pages, if at all.

If I run it in normal mode with NoScript, uBlock and various other add-ons active, it is effectively unusable because pages simply will not load, just sit there with the hourglass on the tab.

I tried to downgrade to the previous version, but it's telling me that my profile is from a later version, so I need to create a new one.

Anyone got any ideas how to fix this as I'm having to post this in Chrome because I can't even Log In here using Firefox!

[Graham_M]

 ADDENDUM: I found the Firefox Task Manager and restarted in Normal mode.

I've got it trying to use 140% of CPU!

[siffemcon]

You could file a bug:

- via the address bar, go to about:config > click 'Copy text to clipboard' > paste to a text file and save it

- via the address bar, go to about:memory > click 'Measure and save'

- file the bug at https://bugzilla.mozilla.org/enter_bug.cgi?format=guided.

- click the 'Attach New File' button to upload your two saved files

[Graham_M]

It seems to have improved slightly after I upgraded again, this time to 136.0.4, but it's still sluggish at times.

I'll try filing a report and see if that gets any report.