Comment # 16 on bug 1197970 from Andreas Stieger

Going by your report in bug 1197973 and this one, the most likely explanation
is that you are using a mix of incompatible repositories. To fix it remove the
incompatible ones and switch all your packages to a set that works. W.g. all to
Tumbleweed. Modulo that, cannot reproduce here: firefox works fine.