EMC KB emc254946  is customer viewable, so not sure why it is unavailable to you. The message is related to GNS enabled device groups. The symptom in the KB is: Customer was adding a second hop causing a remote-mirrored GNS group to become part of a cascaded RDF configuration which caused GNS to fail.  Please make sure you don't have any of these type of DG's with GNS enabled: Any group containing one or more of the following configurations cannot be mirrored with GNS: 
Hi,   I got the below error in the SYMAPI logs:   emcSymValidateGroup  Std devices in cascaded relationship have Hop 2 RA Grp Number error SYMAPI_C_INV_HOP2_RDF_GRP  Can someone help me out with this error?  Thanks.
Error in the SYMAPI logs