I need to click the Thunderbird icon twice

What is your operating system? If it's Windows, that's still called the Task Bar. It's called other things in other OSs.

Yours would be an OS issue, not a Thunderbird issue. I would try removing the shortcut from the Task Bar, then re-adding it

There is an option in Windows File Explorer that makes it so you can open EVERYthing with a single click rather than a double click. I don't suppose that's what you want.

It is Windows 11. I removed it and re-added it. Rebooted. Sadly, the problem remains. " There is an option in Windows File Explorer that makes it so you can open EVERYthing with a single click rather than a double click. I don't suppose that's what you want. " - I have tried that a few times. I am not a great fan of it.

Windows has no built in option to change the single click to a double click. In fact a double click should open two instances of the application you double click on.

Can we try a couple of simple trials to see what might be happening here.

Open the windows task manager Ctrl + Shift + Esc Check the task manager to see if a Thunderbird instance appears in the applications of background processes Single click on Thunderbird in the taskbar. Check the task manager again to see if a Thunderbird instance appears in the applications of background processes

What was the result.?

When Thunderbird installs, it usually placers a link to itself on the taskbar, the desktop and the start menu. Do you have these other links? If you have it on the start menu.

Right click the icon on the taskbar and click to unpin it. From the Windows start menu right click the Thunderbird entry and select to pin it to start (the first item on the menu.

What was the result.?

Thunderbird appears 4 times in task manager.

After click taskbar appears 4 times 1 of which is inbox.

Replaced the taskbar icon.

After my next restart I will see if anything has changed.

Select each of the Thunderbird entries that appears in the task manager when you fist open it and then right click and select end task.

Then try the click on the taskbar again.

I think Thunderbird is running in the background, perhaps even hung and the second click is getting one that loads a window.

Interesting. Killed all 4. 1st click - no response. 2nd click - opened up with 4 entries in the task manager.