Over the past few years, I’ve seen a few instances where ProClarity Dashboard and Kerberos just don’t seem to get along – no matter how much configuration or troubleshooting is performed. One of the symptoms I see is an HTTP 500 error when users try to browse the Dashboard. Our esteemed Sean Flanagan recently solved a similar case and the answer was to verify that IIS ASP.NET was configured to run in 32-bit mode instead of 64-bit mode. IIS was already configured for 32-bit mode since ProClarity is a 32-bit only application. This solution may have been the cause for some of the past failures I witnessed. Here are the instructions for making the switch.
894435 How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit version of ASP.NET 2.0 on a 64-bit version of Windows