This is a bug with Unity exports, for some reason MacOS does not give us (the user) execution privileges for the program. The way to fix it is to move the application to your Applications Folder, then open your Command Line / Terminal, and type cd applications/Digital\ Logic\ Sim/Contents/MacOS && chmod 755 Digital\ Logic\ Sim
So basically what that command does is go to the application, go inside of it to where the actual Executable is, and then run the chmod command, which changes permissions, specifically to 755, which means that the owner (you) should be able to do whatever you want with it
