The window you describe is an error message from the site itself. It in turn is caused by an invalid javascript file.
This is a problem on dubail.fr's end; not a bug in firefox. Perhaps you can try to notify the site owners. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/812234 Title: site impossible to use with firefox To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/812234/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs