Head again to the latest release and download the cb_thunderlink_windows.zip from the assets.

Unzip the cb_thunderlink_windows.zip e.g. to C:\FooBar\cb_thunderlink. This location must be a fixed location (no network location!) and permanently available.

Open a Command promptas administrator and issue :

> cd C:\FooBar\cb_thunderlink
> cb_thunderlink.exe register

It registers the executable to the add-on and it registers the protocols thunderlink:// and cbthunderlink:// to the operating system.

Remove and reinstall the cb_thunderlink.xpi into Thunderbird and that's it. From now on you should have again clickable (cb)thunderlink's!