I found a solution with v6 on both machines, one observation is, why this limitation where we can't load every version plugin bridge coulnd't be load with the last HOST version? Actually, is nosense with those power Silicon, have no possibility to update the HOST because (in my case) the plugin bridge is the "master" and the HOST the slave (old version of plugin brdige "drive the scenario and not viceversa).
Conclusions, we actually have powerfull machines where is possibile to be used as romplers, and, in the studio LAN with old and other various computers obsolete and vintage too, the freedom to use last yuor software without limitations.
hope it's clear, sorry for my english!!