Exchange 2003 and The token supplied to the function is invalid ID: 80090308

Problem: When trying to open Public Folders in Exchange Admin I get the error “The token supplied to the function is invalid ID”

Form Required to View This Message Cannot be Displayed

When I use my calendar to create a new appointment I get the following error: The form required to view this message cannot be displayed. Contact your administrator. Cause: The Frmcache.dat file has become corrupted. Solution: rename the Frmcache.dat file located in the <windows>\forms directory. Then perform one of the following two procedures (A or [...]