Rated 5 out of 5 stars

EDIT: Started working as expected once I installed another add-on, which upon restart opened a window asking if I wanted to install THIS add-on. Very strange, but now it's working perfectly. This seems like a Thunderbird issue and not a MinimizeToTray issue, so 5*

OLD REVIEW:
Not at all working in Thunderbird 60.7.0 32bit on Windows 10 x64

Thunderbird keeps saying it's not installed and asking me to restart even though it shows up in the add-ons section. Closing Thunderbird does not minimize it to tray.