Remote Desktop Connection Broker Client failed while getting redirection packet from Connection Broker. User : Error: Remote Desktop Connection Broker is not ready for RPC communication.
I was getting this in my event log and users could no longer connect to RDS when trialling it
Event ID 1296
Remote Desktop Connection Broker Client failed while getting redirection packet from Connection Broker.
User : DOMAIN\USER
Error: Remote Desktop Connection Broker is not ready for RPC communication.
and then
Event ID 1306
Remote Desktop Connection Broker Client failed to redirect the user DOMAIN\USER.
Error: NULL
I found the Fix for me was
If you edit the properties of your Session Collection, click on the Security on the left. There is a setting for Security Layer. By default it is Negotiate. Try toset it to RDP Security Layer
My users could then connect again, i made the change in group policy for all TS [RDS] servers
Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Security
Edit Require use of specific security layer from rermote [RDP] connections to Security Layer-RDP