RobClack said

I uninstalled and reinstalled Firefox a couple of weeks ago, when this first occurred, and that fixed the problem until today. I'm running Windows 10.

You need to delete the Mozilla folder as well if your doing a re-fresh install to eliminate any problems from before.

I've just reinstalled Firefox having renamed my Mozilla folder and it made no difference. Firefox still hangs when I visit the online banking website. And contrary to a message I had from Firefox, all my bookmarks have now vanished. Since it told me it would restore them, I didn't make a note, and now they've gone. That didn't happen last time.

OK, I swapped Mozilla folders back to my old one and have at least got my bookmarks back. Still can't access online banking.

Hi RobClack,

If your problem did not occur in Safe Mode, it is most likely because of an extension, theme or hardware acceleration.

I read you already tried to disable hardware acceleration. Try to disable all extensions: troubleshoot extensions

Regards

I can confirm the problem does not occur in Safe Mode, but manually disabling all Add-ons did not fix it. I only have LastPass and uBlock Extensions and a single Theme.

OK, the problem is Shockwave Flash Plug-in. If I disable that, I can get to my online banking website OK. Thanks for your help!

ok thanks for sharing