CMMVC6214E The system could not be restored because the backup configuration contains a hybrid system of Storwize V7000 Gen1 and Storwize V7000 Gen2 nodes. Currently this cluster is not Storwize V7000 Gen1 compatible.

Explanation
An attempt is being made to recover a hybrid system from a 

FlashSystem 7300
 config node. If you continue, the
system cannot add Storwize® V7000 Gen1 nodes and the
system will be re-created with Storwize V7000 Gen1
compatibility mode disabled. You cannot readd any Storwize V7000 Gen1 nodes to the system.

User response
If you continue, a former hybrid system will be re-created as a 

FlashSystem 7300
 system exclusively. To continue to
use a hybrid system, restart the recovery from a Storwize V7000 Gen1 node.