User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:57.0) Gecko/20100101 Firefox/57.0 Build ID: 20171006233559 Steps to reproduce: 1. Open firefox. 2. Open a link that you have received in Telegram. (or other application) Actual results: I receive a notification telling: "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system." Expected results: Open the link without problems.