After re-installing Catalina, I added greenshot app via AppStore again. The App appears in taskbar. When using Greenshot, the dialogue "Greenshot needs permission to capture your screen" appears.
When navigating to System Preferences -> Security -> Privacy -> Screen Recording, the area on the right (where the app should appear) is empty. I cannot drag& drop the app to this area either.
-> Greenshot not usable at the moment. > blocker
MacOS Catalina 10.15.5, iMac late 2013 i5
I wanted to pass this to our Mac developer , but saw in the discussions going on that this should be solved with the newest version which is 1.2.19
Can you make sure you got the latest update?
I updated the app manually to 1.2.19 and now it works. Problem solved.
Thank you for the feedback, happy screenshotting!