System.IndexOutOfRangeException: Index was outside the bounds of the array

Product:

Cognos Controller 10.4.2
Microsoft Windows 2019 server

Issue:
When starting and stopping the Cognos Controller client several times you get this error when you try to login.

System.Web.Services.Protocols.SoapException: Server was unable to process request. —>┬áSystem.IndexOutOfRangeException: Index was outside the bounds of the array. at
Cognos.Controller.Proxy.ControllerReportNetService.RepNet.GetUserInfo ….

Solution:

There can be many cause of this issue, but first make sure you do not have previous errors that trigger this.

Logoff cognos controller client and restart your laptop, to ensure there are no excel or controller software running in the background.

Then login and try again.

When you get one error in Cognos Controller, it is best to logoff and restart the client completely to not get other errors as an affect of the first error.

More Information:

https://www.ibm.com/support/pages/error-occurred-while-trying-access-server-systemindexoutofrangeexception-index-was-outside-bounds-array-when-launching-controller-client

https://www.ibm.com/support/pages/troubleshooting-index-was-outside-bounds-array-when-launching-controller-client