Login Active Directory issues for vCenter 5.5

Hi all,

I need some help on setup new vcenter 5.5.  I'm able to login with administrator@vsphere.local.  I'd able to add in identity source for Active Directory via the "active directory" or by LDAP.  Also, able to added AD domain groups or users and permission.  However when I cannot login to vsphere.  I tried to deleted and re-added Identity source AD but no prevail.  One of the webclient error:

"The authentication server returned an unexpected error: ns0:RequestFailed: Group was not found: GroupSID= 'S-1-........'  The error may be caused by a malfuntioning identity source."

Thanks for reading.

Joe