The error was caused by a software called Hipchat which I installed because I needed a package from it. It not just made Firefox, Icecat and Thunderbird stop running, but also caused my System Settings to crash(crash like in "I couldn't even open them.".)
I don't know if the program only causes the errors on my system, or if it is a general problem, but if you experience the same errors and have Hipchat installed, you might want to uninstall and check f the problem persists.
[System is Fedora 20.
I used Firefox, then closed it, wanted to open it again and the above messages occured (mind you that between the last updates and the error, I restarted my computer at least three times). YUM also says that SQLite is at its latest Version.
I wanted to switch to Icecat anyways, but it gives me the same error, probably because it uses Firefox's code.
I already tried what is suggested here: https://bugzilla.redhat.com/show_bug.cgi?id=520339
$ rpm -qa \*xulrunner\* \*firefox\* \*sqlite\*
# rpm -e --nodeps firefox xulrunner # yum install --disablerepo=updates firefox xulrunner
But none of these worked for me.
I'm not sure if a solution for Firefox would work for Icecat, but I will be happy to test it, and just being able to run Firefox for now would be a good thing.]