Thunderbird displays an odd icon in panel bar

[pauldl58]

Thunderbird displays an odd icon in panel bar

[DirkHaar]

It seems you have 2 thunderbird threads/instances open, i.e., TB and your new editing message.
Your panel app "stacks" instances and shows the number of windows/instances...
(I don't this app, so don't ask for the name).
The ugly pencil is part of the theme you chose - my icon is the standard envelope.

[pauldl58]

To DirkHaar:

It worked normally in all the past versions of Linux Mint that I have used. Been using Mint Cinnamon for years.

I added the Thunderbird app to the panel using the same method I always have. I right click the Thunderbird icon in the menu, select "Add to panel".

I click on the icon that was added to the panel to open Thunderbird as I always do. The ugly icon is something new.

Again version 21.3 didn't do this.

This is definitely a bug, not user error. 20+ year Linux user.

Theme: Mint L Aqua ( nothing exotic )

Thanks for trying to help.

[mtwebster]

This will be fixed in the next thunderbird release. For now if you'd like to apply the fix:

Edit /usr/share/applications/thunderbird.desktop (as root), around line 106 where it has StartupNotify=true, add or insert:

StartupWMClass=thunderbird-esr

[pauldl58]

Thank you