Please uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved.

Install Firefox Final Release Version 57 https://fileforum.betanews.com/detail/Mozilla-Firefox-for-Windows/1032985422/1 they get the files a day early. Note : Legacy Extensions will be disabled and or removed. Will be on Mozilla servers tomorrow/full/update.

The above link will update your but since have issues is best to pull the folders and cleanup.

Please let us know if this solved your issue or if need further assistance.

Thanks for the quick reply Pkshadow, but uninstalling everything and getting rid of my folders is not a good answer for me. I looked at the link you provided and it seems FF is content on killing everyones add ons and Stylish scripts for "speed" as FF 57 doesn't address my original question/problem. Hopefully someone savvy with FF will see my question and know the answer.

Lircbeacher said

Thanks for the quick reply Pkshadow, but uninstalling everything and getting rid of my folders is not a good answer for me. I looked at the link you provided and it seems FF is content on killing everyones add ons and Stylish scripts for "speed" as FF 57 doesn't address my original question/problem. Hopefully someone savvy with FF will see my question and know the answer.

That's fine if do not like a solution. I hate going through spiel the W3C.org (World Wide Web Consortium} makes the rules governing standards and practices for web browsers and web pages as well as future considerations of code for both. So with that Mozilla had no choice but to update to the current standards and practices. ...... That is the way it goes. Sorta like making seat belts mandatory in cars and motorcycle helmets.

I like that there are other people who are up on/research the rules governing standards and practices for web browsers like myself, however there is no rule that my original problem is REQUIRED to be incorporated into the FF browser. Seat belts are GOOD....helmets are GOOD (especially since they saved a lot of my friends lives). I'll now wait for other members input/responses/possible solutions.

Stylish recently moved from Legacy extension (2.1.1) to WebExtension (3.0.1) and in the process it lost the ability to touch the UI. To hide a menu item or modify the UI in other ways, you can put custom style rules in a userChrome.css file. Probably you can copy/paste the user style you have been using up to now and there's a good chance it will continue to work.

I recently posted a site with information about the userChrome.css file. When you have 5 minutes: https://www.userchrome.org/

Thanks for the reply Jscher2000. Seems like your answer is the only solution I could find also for the latest FF release. I'm thinking I'm just going to install an older version of FF and just not update it.

If you want to defer the excitement for five months, you can install the Extended Support Release of Firefox 52, which will receive security updates through next Spring.

https://www.mozilla.org/firefox/organizations/faq/

Although originally designed for large companies, ESR is used by numerous individuals who require support for legacy plugins or XP/Vista.