Firefox does not complete startup.
Does not open a startup page. Stops when the initial Firefox grey-out displays (Tried to send screenshot. Upload still churning after several minutes). Firefox Icon shows in current apps list and can be Force-Quitted. Does not appear in the Recent-Apps menu.
Began when I clicked on a Steam/Rimworld Button link to "Rimworld User Forum". Didn't show URL.
Wšě wotmołwy (2)
Uninstall Firefox and then reinstall from the Full Version Installer. https://www.mozilla.org/en-US/firefox/all/
I suggest you check this and follow : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware and https://www.malwarebytes.com/adwcleaner/ Save the reports, do not clean and https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/ Post in only 1 forum only and wait.
Please let us know if this solved your issue or if need further assistance.
Note that the OP is using Mac OS X 10.11.6
Try to start Firefox in Safe Mode to see if that works.
- Mac: hold down the Options key while starting Firefox
- Windows: hold down the Shift key while starting Firefox