Webstation error," Could not load file or assembly 'IKVM.AWT.WinForms' or one of its dependencies. This assembly is built by a runtime newer than the currently loade...

[Product_Support]

Issue

When trying to open TAC Webstation the following error message appears:

Webstation error," Could not load file or assembly 'IKVM.AWT.WinForms' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded."

Environment

Vista 5.1.5,
Windows 2008 server 64 bit

Windows 2003 server

Cause

Wrong Application pool is used for Webstation in the IIS, a ASP.Net version 2 is used instead of a .Net version 4.
Webstation 5.1.5 is developed in ASP.Net 4.

Resolution

 In the IIS, under Websites\Default Web Site\Webstation - right click and select Properties and then the ASP.NET tab, change the Application pool from the DefaultAppool(ASP.NET version 2) to SE ASP .NET v4.0 classic (ASP.NET version 2) Application pool.