This is a problem that I occasionally see crop up in customer environments, but until now I had never bothered to document the issue.
Customer is able to log into the web console successfully but when they click on certain views like the active alerts view they see the following error:
Anytime there is an issue with the web console my first suggestion is to attempt to recreate the problem as localhost on the machine that hosts the webconsole. If the server has the same problem locally you know where to start troubleshooting, if it is only happening on client machines it could be firewall or some problem at the client level.
When we tested from SCOM web console server we get the same error, but this time with a little bit more information:
This may not seem useful, but this is actually telling us exactly where the problem is. Note the Version=18.104.22.168 in regards to .Net Framework. This is telling what version of the Framework is expected for this particular app pool.
If we navigate to IIS we see the following:
OperationsManagerMonitoringView is set to v.40, but it should be set to v.2.0. We need to edit the Basic Setting and select the drop down with v2.0
After that we need to recycle the Application Pool via the Application Pool task
Then just logout of the webconsole and back in and all will be well.