WSUS Error: Connection Error

We started experiencing issues with the WSUS server recently. I wasn’t able to connect to the WSUS server using WSUS Administrative console.

When I have tried to connect I got the following error message:

Error: Connection Error
An error occurred trying to connect the WSUS server. This error can happen for a number of reasons.
Click Reset Server Node to try to connect to the server again.

After the restart of the WSUS server I was able to use the console but after some time the WSUS server run into the same problems again.
We have checked application pool on the WSUS IIS server and have discovered that the WSUS Pool was down. After we started the WSUS Pool, we have temporarily fixed the problem, but after a while, it crashed again.

Event Log had several logs related to this problem like:

Event 5013, WAS – A process serving application pool ‘WsusPool’ exceeded time limits during shut down. The process id was ‘3504’

Event 5002, WAS – Application pool ‘WsusPool’ is being automatically disabled due to a series of failures in the process(es) serving that application pool.

Have in mind that errors appeared under different Event ID’s and Process ID’s.

To fix this we had to disable Rapid-Fail Protection and raise Private Memory Limit.

Here’s how to do it:

Login to your WSUS server, open Internet Information Services (IIS) Manager.
In the left pane, expand the WSUS server and click on Application Pools. If it is down, start WsusPool application pool and right click on it.
Now select Advanced Settings and do the following:

Under Rapid-Fail Protection change the Enabled value to False.
Under Private Memory Limit (KB), change the value to 3145725 or 3.1GB which is recommended by Microsoft.

Hope this helps.