During an upgrade, Horizon 7 does not support View Composer provisioning and maintenance operations. Operations such as provisioning and recomposing linked-clone desktops are not supported during the transitional period when any Horizon 7 servers are still running the earlier version. You can successfully perform these operations only when all instances of Horizon Connection Server and View Composer have been upgraded.
Note: Before you can use the View Composer 6.2 feature for creating automated farms of linked-clone RDS hosts, you must upgrade all Horizon components to Horizon 6 version 6.2 or later.