Then this issue requires personalized help, perhaps even a remote session. We need to see what's with your VM that prevents the screen image from being captured. Let me create a support ticket based on this forum thread. I'll contact you through the ticket soon.
If so, this is rather an RDP/VMWare problem. Remote Utilities' RDP mode just launches the native Microsoft RDP client for you. If Internet-ID connection is used, then RU simply acts as a tunnel - it doesn't get in the way of how RDP works.
Here is some info from the Internet on the subject:
As of now it looks like Viewer becomes disconnected after being inactive for a certain time.
This is not a program's feature. It looks like a connectivity problem. It would help looking at the Host log - feel free to create a support ticket and submit your Host log/logs for examination. The Host logs are located in C:\Program Files(x86)\Remote Utilities - Host\Logs\