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?
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?