OSStatus error 99999 on macOS Mojave 10.14.6
I asked this question a while ago ( https://discussions.apple.com/thread/250924588 ) and got no response.
After some more digging, I found if I disabled the gatekeeper and then opened the application, it would still work after I re-enabled the gatekeeper.
sudo spctl --master-disable
Then I opened the application, and then re-enabled gatekeeper:
sudo spctl --master-enable
So frustrating!
MacBook Pro Retina