Trying to patch one of my administrative servers and was receiving that error message. Server is 2016 standard, domain-joined, and there is WSUS in the environment along with the associated GPO’s for WSUS use.
Looks like this error is/was received due to the fact that my WSUS server was experiencing some issues.
- Log into WSUS
- Open IIS Manager
- Navigate to Server Name > Application Pools
- Find WsusPool
- Start (or restart) this pool
In my case the pool had stopped due to an issue encountered when running a WSUS cleanup script. Starting it and then re-running the update check (retry button), yielded much better results.