HI!
When migrating data extracted from a 2.3.39 server via slapcat into a RE24 server I had two issues:
1. Option -q of slapadd resulted in a seg fault.
2. I had to remove the entryCSN attributes from the LDIF data. Probably this is somewhat related to the 2.3-2.4 replication issue.
Ciao, Michael.