hi, thanks for reporting this. after reinstalling firefox 57, could you go to the firefox menu ≡ > help ? > troubleshooting information page and take a look in the Accessibility section if accessibility is set to "true" there.

if yes, can you please copy & paste this whole section into a reply in the forum and see if the following fixes the performance problem: go to the firefox menu ≡ > options > privacy & security panel and under permissions check the setting to prevent accessibility services from accessing your browser.

Thanks a ton! Your solution fixed the problem

I have used the above solution and now hope it will work. I had problems with the top bars changing colour by themselves. I had to disable my theme and re-enable.

I hate the fact that I can no longer colour my tabs - the add on is not compatible.

I just spent hours trying FF57 on my Windows 10, and had the same issues. I tried 3 separate times to get it working and the same result every time, my system basically froze. I then spent a good chunk of time getting FF56 working again with updates shut off, and my extensions set up, etc. Not sure it's worth the effort of tearing that all down again, until there is an upgrade that fixes this problem as part of the upgrade. Is there a patch release expected with this fix that I can use to upgrade? If so, when?

Since my comment earlier, all is working fine and I have found a nice pastel theme with soft different colours and the whole thing looks much better. It's certainly working OK

PER YOUR INSTRUCTIONS: if yes, can you please copy & paste this whole section into a reply in the forum and see if the following fixes the performance problem: go to the firefox menu ≡ > options > privacy & security panel and under permissions check the setting to prevent accessibility services from accessing your browser.