In your Exchange 2013 environment, you may come across the following error below when working in the EAC when you are trying to configure delegation or trying to modify user accounts:
The Object <object DN> has been corrupted and is in an inconsistent state. The following validation errors happened:
The access control defines the ObjectType <Object Guid> that can’t be resolved.
To do some troubleshooting, you could check if the above mentioned SID is not a deleted object, you can view the Active Directory recycle bin to see if it is. You can also use the PsGetSid tool to find it.
Alternatively, you could restart your Exchange 2013 servers and see if the errors clear.
Hope it helps.