TeamViewer 12 Host

With TeamViewer 12 Host I can connect easily every time to two PCs but with one PC, when I try to connect via TeamViewer I get the message "Initializing display parameters" and it hangs. If I Remote desktop to this troublesome PC from one of the other PCs I can then TeamViewer connect to the troublesome PC though I get a Windows message "Windows Explorer is not responding" (I take the "Close the program" option). If I then close the Remote Desktop connection to the troublesome PC, TeamViewer shows the message "The screen cannot be captured at the moment. This is probably due to fast user switching or a disconnected/minimized Remote Desktop session.". What do I need to chanfe so that I can directly TeamViewer connect to the troublesome PC?