So I just checked the log:
When attempting to start Mafia II with the watcher enabled I see the following error in the log file in the temp directory:
ERR: VorpControl Injector StartProgram: DLL not found or invalid.
And from the troubleshooter:
INF: VorpControl: Starting elevated (64bit, version 17.2.1).
INF: VorpControl: Starting elevated (32bit, version 17.2.1).
INF: VorpControl Injector InjectVorpD111: DLL injected: mafia2.exe (mode1).