I couldn’t open the application until I changed the browser I used for downloading the *.zip. The solution: It works with Safari, but not with Chrome.
I’m admin for my Mac with Catalina (Version 10.15.6) and got this as an error message:
LSOpenURLsWithRole() failed for the application /Users/XXX/Desktop/Antetype Web.app with error -10810.
All quarantine commands didn’t work so I just switched from Chrome to Safari.
I just wanted to provide this solution in case somebody else has the same problem.