Take a look at this article, maybe it will help:
Make sure that the power and cryptographic services are running, and McAfee Validation Trust Protection Service is not set to disabled, and is running. Also then confirm that the McShield service is running and not set to disabled.
In previous version of VSE, when installing VSE, I was asked if Windows Defender should be disabled. Apparently, I now have to do this separately. That helped, anyway. Is this normal?