Active Directory Domain Services attempted to add a crossRef object, but the directory partition name reference (nCName attribute) ...

Active Directory Domain Services attempted to add a crossRef object, but the directory partition name reference (nCName attribute) conflicts with another object because there are two directory partitions with the same nCName. This could have occurred when the crossRef object was added or deleted, the partition was deleted, and the crossRef object was added again. 
 
CrossRef object: 
%1 
Old directory partition name: 
%2 
New directory partition name: 
%3 
 
Active Directory Domain Services usually attempts to automatically correct this conflicting name reference, but another directory partition that has this name exists. 
 
User Action 
Manually delete one of the crossRef objects corresponding to the directory partition that should not remain in the forest. If you chose to keep the crossRef object with the conflicting name, you must run Dsdbutil semantic analysis to correct the name reference. 
 
Additional Data 
Error value: 
%4 %5