User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.10) Gecko/20071115 Firefox/2.0.0.10 Build Identifier: Version 2.0.0.9 (20071031) If the profiles.ini points to a directory that does not exist, the error message is something like "Thunderbird is already running, but does not respond. In order to open a new window you have to kill all existing Thunderbird processes or restart your computer." (Translated from the German version). This is very misleading as there are no running processes. Reproducible: Always Steps to Reproduce: 1. Configure a profile in Thunderbird and close Thunderbird 2. Edit the path parameter profiles.ini to point a not existing direcotry, save file 3. Start Thunderbird Actual Results: Misleading Error message Expected Results: Error message "Profil not found in %direcotry%!" Normaly the problem should not occur, but when restoring a profile or having a faulty profiles.ini the error message is very misleading.