Hello guys, here is the solution if it does not open on macOS. First, move the app to Applications folder. Open terminal, and type "cd /Applications/Digital-Logic-Sim.app/Contents/macOS" Then type "chmod +x Digital-Logic-Sim" Now, try opening the app again. If you get permission denied, open settings then privacy and security, then allow the app anyway. (It is not a virus, just a false alarm.)