The mapiID value for the following attribute duplicates the mapiID value for an existing attribute. Attribute: %1 (%2, %3) ...

The mapiID value for the following attribute duplicates the mapiID value for an existing attribute. 
 
Attribute:
%1 (%2, %3) 
Existing attribute:
%4 (%5, %6) 
 
Both attributes are considered deactivated (as if the isDefunct attribute value were TRUE). The condition will resolve itself after the schema directory partition has replicated successfully. 
 
User Action
If this event continues to occur, initiate a replication cycle with all replication partners of the local directory service. If the condition persists, deactivate one of the above classes by setting the isDefunct value to TRUE.