I'm having a similar problem - tried nightlies - nothing worked. The only thing which is working - start the application as Administrator (Right click on executable). With this I'm able to write this here... maybe it also helps you? I also tried to debug it (see https://developer.mozilla.org/en/Using_the_Mozilla_source_server ) but could not find anything useful (it's crashing in a thread with no valid backtrace ...)