Whenever I restart my Mac, Thunderbird opens as a download instead of just being able to use from the Dock
Whenever I restart my Mac Thunderbird opens as a download instead of just being able to use from the Dock. This is driving me up the wall. If I try downloading another copy it just adds it as an alias. I have one copy of Thunderbird with a black arrow pointing towards it from the lower left in my Applications folder. It all works fine, but if I have to do a restart and click on Thunderbird in my Dock it opens as a box asking me if I trust it as it's a download etc. and it reloads.
Additional System Details
- User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0.3 Safari/605.1.15