If the error pop states you cannot open the application, start the terminal and key in:
chmod +x SomeApp.app/Contents/MacOS/*
Example, chmod +x The Spellbook 0.5.5.1 MacOS.app/Contents/* or chmod +x The Spellbook 0.5.5.1 MacOS.app/Contents/MacOS* if the first one does not work.
If you need admin rights then include the command : sudo chmod +x The Spellbook 0.5.5.1 MacOS.app/Contents/MacOS*
Reference:
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After running the command, you should be able to open the app. However, if the app still crashes then is a different issue all together. Might be a bug in the game app