5a693e87_Plus__known_issues____RealVNC___Workaround
[ID] 266 [Description] Mounting an image and then rebooting to an operating system (rather than to the image) may cause the host computer to crash. [Status] Won't fix. [Workaround] 
Power the host computer off using its physical Power button, and then reconnect.
VNC® Viewer Plus (known issues) - RealVNC®
Workaround