An error occurred while trying to access server

Product:
Cognos Controller 10.4.2
Cognos Analytics 11.1.7
Microsoft Windows 2016 server

Issue:
After a windows patch, no one can login to cognos controller.

Error:

An error occurred while trying to access server…

System.Web.Services.Protocols.SoapException: Server was unable to process request. —> System.IndexOutOfRangeException: Index was outside the bounds of the array….

Solution:

Login to Windows server where CA11 and Cognos Controller IIS are.

Launch a command prompt
Type the following:    IISRESET

 

Check if you can login to Cognos Controller, after above restart of www service.

More information:

https://www.ibm.com/docs/en/cognos-controller/10.4.2?topic=controller-error-occurred-while-trying-access-server