Hi, please try : 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 If the issue is still there suggest run a Microsoft Trouble Shooter for the issue. In the search bar type Trouble Shooting. Try : *Repair System Registry and Files Find the Dos Prompt Right or Powershell 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. If all fail : 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.

Hello, I have tried Firefox in safe mode and it work fine so I restarted Firefox and it seems to be working fine now, it seems like Firefox was having a funny 5 mins. Thanks for you help. Matthew