When attempting to add more than one incoming Replication job to a DL1000 Appliance, you receive an error message to tell you that the DL1000 Appliance is limited to one incoming Replication.
The same message may be seen when trying to add a second outgoing Replication to a DL1000 Appliance.
This is expected behaviour.
See also the following KB solution in relation to DL1000 sizing and limitations:
https://support.quest.com/kb/147100
DL1000 Appliances are limited to one incoming, and one outgoing replication.