I'm guessing this happened on your Mac, right? You can see if this helps? https://itch.io/t/3177769/application-cant-be-opened-on-mac
You can also try this: https://forums.rpgmakerweb.com/index.php?threads/need-some-help-cannot-open-a-ga...
Viewing post in Pokemon Underground: A Fetish Diary comments
Last resort: try a Windows emulator? https://www.geeksforgeeks.org/best-windows-emulators-for-mac/
I'm sorry that I can't be of more help. I don't use a mac myself.