When you migrate groups with the Active Directory Migration
tool, you may receive the following error message in the Active Directory
Migration log file:
SID History cannot be updated for
group because the SID for
group already exists in the forest. rc=8539.
A net helpmsg for 8539 yields the following error text:
The source object's SID already exists in destination
forest.
This error can be caused by renaming the group and then
migrating it again. The security identifier (SID) in the SID history can only
exist in one place in the forest.