Comment 1 for bug 1213584

mdd5 (mdd5) wrote :

I had the same exact problem
Seems to be an issue with the User-Agent-Switcher https://addons.mozilla.org/de/firefox/addon/user-agent-switcher/

Because I have tried another
https://addons.mozilla.org/en-US/firefox/addon/user-agent-overrider
and it worked perfectly.