System.NullreferenceException Error When Starting Controller Client

Product

Cognos Controller 8

Symptom
System.NullreferenceException: Object reference not set to an instance of an object. At cognos.controller.appcontext.initConfig()

Problem
This error occurs when Cognos Controller is executed from Cognos Connection or when the URL http://servername/cognos8/controllerbin/ccr.exe is executed

Cause
.NET component is not correctly registered in IIS

Solution
Register .NET in IIS
Steps:
1. Open a DOS box.
2. Browse to C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727 directory
3. Type aspnet_regiis.exe /i