Hi Mooreted,
Thanks for your post.
>> We have been having issues with a blank screen when users log off.
Are there any related event messages logged when black screen occurred?
Does the Black Screen go away if press Ctrl+Alt+End then click Esc?
>>I noticed something interesting: When a local user is logged in and I remote to the server, I can choose to "Disconnect User"
or "Log off User".
You can disconnect a user from a session in Remote Desktop Services Manager by using the disconnect action.
https://technet.microsoft.com/en-us/library/Cc754397.aspx?f=255&MSPPError=-2147217396
In your scenairo, you don't have Terminal Server roles installed. But you could remote to the server, right?
You could also check the following article for a reference.
https://technet.microsoft.com/en-us/library/cc771694.aspx
Best Regards,
Mary Dong