Whenever I try to open Firefox, I get a window that says Choose User Profile. Whenever I click on default it says that profile can not be opened because it is in use, but I don't have any windows opened. Anyone know how I can fix this?
Check your running processes and see if Firefox is there even though you don't have it opened in a window. If it is, end the process. For me Firefox won't always open because it's running even though I've closed it. After I delete it out of the running processes though, it works again.
This happens sometimes with Mozilla as well. If ending the process doesn't work then just restart the computer.
I had that problem a few releases ago because I didn't completely uninstall the old one and installed the new one on top of the existing old one. Yall might try uninstalling it all and reinstalling... at least that's what worked for me.