If you see this displaying, it's a result of changes Apple has made to their Gatekeeper system.
All software built for the Mac OS after June 1 of 2019 must be uploaded to Apple’s servers, scanned by an automated system, and approved. If it isn’t approved by Apple, the Gatekeeper feature of macOS won’t let it run—at least, not by default. Instead, it’ll display an alert that Apple can’t scan the app for malware and tell you to contact the developer for more information.
We're working on getting the game approved by Apple, but this is unfortunately not a quick or easy process.
Thankfully there is a workaround for now. To get the game to run, control-click on the app launch shortcut and choose Open. You’ll see a similar alert about malware and contacting the developer, but now there will also be an option to just go ahead an open the app. Once you do that, it'll run without needing that step in the future.
If you are running your game through steam and are having issues you can use the fix listed above by right-clicking on the app in your Steam library, then selecting Manage -> Browse local files. You should see the app file in its folder on your MAC. Then Ctrl+Left Click on the game launcher (OOTP Baseball 20.app or FHM 5.app) and click on "Open". Then the game should run.
If you try the above steps and are still not able to run the game, then please fill out a support ticket and we'll do what we can to help you further.