Sounds like you restored a backup from one server to another. This is fine, but you need to adjust dcr.ini to make the domain IDs unique on each server. Edit NMSROOT/lib/classpath/com/cisco/nm/dcr/dcr.ini, and make sure the DCR_ID value is unique on both servers. It's best to adjust the value so that the hostname is used in both cases.
Out of curiosity, could both DCR_ID and GROUP_ID ever become identical across both servers, after restoring one's backup to the other? If so, how would one find out what the second (the restore target) server's DCR_ID is really supposed to be?
