Provide an example (link) of an image that hangs the browser. Also, where are you trying to save it?

It doesn't matter where I try to save an image from, facebook, pinterest, google images, everywhere I've tried gives the same result, even regardless of file type (jpeg, png, webp). Trying to save to my pictures folder, tried saving to separate physical drives and still get the same problem. If I copy the link to any image from within Firefox, and paste it into Chrome, Brave, or Edge, I can save the image via the other browsers without any trouble at all.

What security software are your running? See if there's a policy active. ---> about:policies see screenshot

Are you running pro or home version of Windows? If pro, you should have sandbox enabled for testing. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

Just Windows Security on Win11 Home.

Did you try to wait a bit longer (one minute or more) to see if you can get control again?

Note that this can happen if you previously saved a file to a removable drive that no longer is available , you may have to wait until this request times out.

I've given it several hours overnight to resolve itself without any luck. I haven't saved anything to any directly connected removable drive on this particular PC since building it last August, and everything is up to date. I've tried doing a refresh, full uninstall and fresh install of Firefox, tried without Chrome or Brave installed, everthing I can think of without a complete wipe and fresh Windows install.

What security software are your running? See if there's a policy active. ---> about:policies see screenshot

Did you look at this?

jonzn4SUSE said

What security software are your running? See if there's a policy active. ---> about:policies see screenshot

Did you look at this?

Yes, the result was as pictured.

Do you happen to use the Windows On-Screen Keyboard (OSK)?

Do you have any software that adds shell extensions to the File Manager context menu?

Try clearing the Most Recently Used (MRU) lists with a file cleaner or MRU-Blaster.

Yes I use the on-screen keyboard, but why would that suddenly be affecting Firefox?

Shell extensions, not sure, probably have some.

MRU - I've scrubbed everything I can, short of a full format and reinstall of Win11.

I think I've found the cause: it's on-screen Windows keyboard! I've noticed that after starting on screen keyboard, Firefox hangs the same way. Next, if OSK started, every CTRL+O causes Firefox to hang.

https://support.mozilla.org/en-US/questions/1426377#answer-1614543

Well this problem has now become worse, even without using the on screen keyboard, Firefox just locks up at random now. So unless there's an update that fixes it within the next week, it looks like I'll be removing Firefox from my system completely.

Firefox just locks up at random now.

That sounds unrelated, please create a new question for this new issue.