Customers disabling the use of RC4 for kerberos tickets cause vCenter (and potentially other products) to fail authentication.
This could have likely followed implementing the below MS November patches, which introduced events that warn of RC4 related connection requests.
Cumulative updates:
Standalone Updates:
vCenter is attempting to authenticate using RC4 on a domain where it is disabled. This is likely due to the vCenter computer object being limited by the ms-DS-SupportedEncryptionType attribute. It's also possible that the default encryption attribute (DefaultDomainSupportedEncTypes) of the domain is set to use only RC4.
In the Windows Domain controller logs, filter the security section via event IDs 4769 and 4768, then search for the VC computer account entry.
If the "Ticket Encryption Type" is not 0x12, and using an RC4 0x17 or 0x18 then this is most likely the issue
Implement the Microsoft out of band patch on all Domain controllers in the environment :
Then apply one of the following :
Option 1
Option 2