I have for many years been using the following command to shadow RDP sessions on our Terminal Servers:
exe /control /noconsentprompt /shadow:9
However on Friday I noticed that this stopped working. When I run the command I receive a small window titled "Shadow error" which states "Unspecified Error". This happens on both of our Server 2016 terminal servers. I have already run RSOP to confirm that the correct Group Policies are still being applied. The setting "Sets rules for remote control of Terminal Services user sessions" is the same as it has always been, at "Full Control without user's permission". I am executing the command as the domain administrator and have full rights. Nothing has changed that I know of, except that on Friday we had those out-of-band updates from Microsoft pushed out to address Spectre and Meltdown.
Is anyone else out there experiencing this problem? Any ideas for a fix? There is nothing being logged to event viewer for me to troubleshoot.