Helpdesk site crashing after credentials are entered:
Description: an unhandled exception has occurred during the execution of the current web request... Exception Details: System.MissingMethodException: Method not found: 'Void System.Security.Claims.ClaimsIdentity..ctor(System.Security.Claims.ClaimsIdentitiy)'
See screen shot attached for full error
After uninstalling .net Framework 4.6.1 the website issue appears.
After Uninstalling KB3102467 to remove the .NET Framework, uninstall these .NET Framework Updates as well:
Per 12-May-2016 on Windows Server 2012R2 these are: