HI, are you sure it is not something you have created your self as Greasemonkey is a userscript manager made available as a Mozilla Firefox extension. It enables users to install scripts that make on-the-fly changes to web page content after or before the page is loaded in the browser.

Check this as there appears to be an issue that only affects users who have turned off Cleartype Font rendering within their Windows Settings. So a workaround for the moment would either be to turn Cleartype back on or disabling hardware acceleration in Firefox: *https://support.mozilla.org/en-US/kb/performance-settings

Please try this : SAFE MODE

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

In Firefox Safe mode these changes are effective:

• all extensions are disabled (about:addons)
• default theme is used (no persona)
• userChrome.css and userContent.css are ignored (chrome folder)
• default toolbar layout is used (file: localstore-safe.rdf)
• Javascript JIT compilers are disabled (prefs: javascript.options.*jit)
• hardware acceleration is disabled (Options > Advanced > General)
• plugins are not affected
• preferences are not affected

TEST''''is issue still there ?

if is : As for installing Firefox it can be done in 7mins with all and everything saved. uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 59.0.1 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

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

Ok I've enabled safe mode now. I can't call the issue on demand so I will wait and see if it occurs again and report back. I've also removed all my old Greasemonkey scripts in case one of those were responsible. ClearType is enabled on my PC.

The Facebook issue did indeed disappear in safe mode. So something disabled by safe mode is the cause...

Performed a full install as instructed. However the problem persists. For some reason my current tabs and all my addons were not reset by the uninstall so I think I just wasted my time. Is there a way to do a forced uninstall that actually gets rid of EVERYTHING?

I'm slowly running out of patience. Once I reach a certain annoyance threshold, I'll have no choice but to do the unthinkable, and look for a browser elsewhere. Very sad after using Firefox, basically my entire life.

Hi, well unless you went into the c:\Users\appdata folder all things would have returned, as that is where your Profile is stored. https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

If you backed up as per my instructions your bookmarks and Profile are at hand to reinsert again if you deleted the Profile. As per Restore : https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles and you open Bookmarks and import them. So nothing should have been lost if you followed the instructions.

Was that install with the 59.0.2 Firefox released this date and from a full version installer, link was provided.  ?

Mozilla does not recommend using 3rd party programs to uninstall. https://www.revouninstaller.com/revo_uninstaller_free_download.html

Windows 10 search bar please type Troubleshooter and Right Click and Run as Admin. Note what was fixed.

• Repair System Registry and Files

Find the Dos Prompt or Powershell, Right Click and Run as Administrator then : Copy/Paste to Dos Window : DISM /Online /Cleanup-Image /RestoreHealth then hit Enter. Reboot when completed. Note : DISM goes up to Microsoft for new ones.

Thanks for the reply!

I have all my bookmarks etc stored by Firefox Sync so a backup wasn't necessary. Nothing was lost, except the time it took to reinstall.

Yes I updated with the provided link, to the latest version.

I did use Revo Unistaller with Safe setting and that only removed 2 registry settings additionally.

soulstenance said

Thanks for the reply! I have all my bookmarks etc stored by Firefox Sync so a backup wasn't necessary. Nothing was lost, except the time it took to reinstall. Yes I updated with the provided link, to the latest version. I did use Revo Unistaller with Safe setting and that only removed 2 registry settings additionally.

Maybe next time do not use the safe setting... fyi Just from what I see on this end you should make backups still.

Well if you run in safe mode and the issue is not there then it is add-ons https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes or Profile. Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

You can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem. Never work with original files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

That is about it as running out of options....solutions to offer

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

Ok. I'll try rolling back addons and/or my profile to see if I can pin down the issue. By the way, your link to Troubleshooting Extensions and Themes gave me this error:

"An Error Occurred Oh, no! It looks like an unexpected error occurred. We've already notified the site administrators. Please try again now, or in a few minutes."

So the first add-on I disabled was Greasemonkey, and the problem appears to be gone. As far as I know, the only script I had was one that disabled the timer on memrise.com. I wonder if the add-on itself could be causing the issue. Is there a way to completely reinstall an addon from scratch?

Anyways, thanks for all your help!