I had no problem like this until Ubuntu 21.04 (which I upgraded to lately). Clicking on mailto-links in Firefox result in the error message by Thunderbird "TB already running..." I have FF 88.0 and TB 78.8.1 - system is 64 Bit. I recently had a problem (since the aforementioned upgrade) with Firefox not able to open tabs or windows when clicking on a link in an email (in TB), but today it was gone. Maybe as a result of an update I received yesterday?
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/711305 Title: Thunderbird is already running, but is not responding. To open a new window, you must first close the existing Thunderbird process, or restart your system. Error received when clicking a mailto link in firefox. To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/711305/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
