[Bug 711305]

[Antishape]

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 Mozilla
Bugs, which is subscribed to Mozilla Thunderbird.
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