Symptoms

Receiving error Server Error - validTo
 

Diagnoses

We are getting Server Error:

Specified argument was out of the range of valid values
Parameter name: validTo

Internally all appears to work correctly. It also appears to work with IE11 but not with firefox. the Users seeing the issue are running Windows 8.1.
 

Resolution

Fix supplied by Labs team. New error was generated that involved the token expiring. We increased the token lifetime in Identity web.config: of "SessionTokenLifetime" and "MaximumTokenLifetime" values to 84000 (23 hours).