HTTP Error 500.21 Internal Server Error logging into WebClient. or ASP.NET setup custom has stopped working when trying to register .NET 2 using aspnet_regiis.exe

Issue

After completing the installation for 2.0 WebClient the first attempt to logon results in HTTP Error 500.21 Internal Server Error logging into WebClient.

Trying to register .NET 2 using aspnet_regiis.exe produces  ASP.NET setup custom has stopped working.

Product Line

Andover Continuum

Environment

WebClient

Cause

.NET 4 not registered with IIS

Resolution

Register .NET 4 with IIS from Command Prompt (NOTE: Run command prompt as administrator)