I reinstalled the browser. The bug still occures. Anyway I'm not gonna use Firefox any more because of the bug 783889:
https://bugs.launchpad.net/null/+bug/783889
I reinstalled the browser. The bug still occures. Anyway I'm not gonna use Firefox any more because of the bug 783889:
https:/ /bugs.launchpad .net/null/ +bug/783889