I'm not sure what causes your problem because I've just downloaded the application from the link provided by SI, and I had no problems installing and running it on my Windows 10 computer.
Judging by the message of the error that you get, I can only guess that the application is already running. Open the Windows Task Manager, look for an entry called TMMonitor, then close it and try to run the application again. Also, don't forget that the tool automatically goes to the system tray in case it appears that nothing is happening.
If you got this error while trying to install the application, you probably have a different installer running. Try restarting the PC and don't forget to run the installer with administrator privileges.