It is not uncommon for Anti-Virus programs to interfere with how STEAM and/or Game operates e.g. Anti-Virus inadvertently stops you from being able to launch the game!
We recommend setting up your Anti-Virus to make sure that it does not conflicting with STEAM and your Game! Please add Steam and Motorsport Manager to your exceptions. How to do this will depend on your anti-virus, we very much suggest you searching online on the programs website for details on how to do this.
For clarification by default Steam and Motorsport Manager will be installed in the following locations:
Steam – C:\Program Files\Steam
Motorsport Manager - C:\Program Files\Steam\steamapps\common\Motorsport Manager
If you think it’s your anti-virus causing the problem and don’t know how to configure it to work, it may be worth you uninstalling the anti-virus program.
If you choose to do so, we recommend turning on Windows Firewall/Windows Defender. On OS’s earlier than Windows 8 or 8.1 we’d recommend installing Microsoft Security Essentials which is solid, free and doesn't conflict with Steam or MM. If you run Windows 8.1 or 10 you will already have Windows Defender installed, we would not suggest installing another anti-virus as well as this can sometimes cause conflicting issues.
Once you have setup your anti-virus as above (either with exceptions or uninstalled), we’d suggest uninstalling and reinstalling Motorsport Manager.