Exchange 2013 CU6 +KB2997355 Fix causing ECP 500 Unexpected Error

Hello,

I am experiencing something strange to the Administrator user only.  After upgarding to CU6 and applying KB2997355 the administrator cannot log into ECP but it can access OWA.  The funny thing is all other Exchange 2013 user can access OWA and ECP but the administrator can only access OWA and not ECP which gives a 500 Unexpected Error.

I delete and rebuilt the virtual directories and still nothing.

Please help!!

Thanks,

Nelson