Demo doesn't work on macOS 10.12.6, I always see following error

Hi Garfeild!

That might be caused because a problem with permissions, check this link out: https://help.yoyogames.com/hc/en-us/articles/216753168--Downloaded-app-is-damaged-and-can-t-be-opened-

In addition other possible solutions:

https://discussions.apple.com/thread/7682929

https://howchoo.com/g/yty3mdvkyty/how-to-download-apps-from-anywhere-in-macos-si...