Error Code 216

When I play with my friend (John), who lives in the same household as me, only the party leader will be able to load into the game and the other person will receive a banner showing error code 216. eg. if John and I were in the same party and he is the leader and he starts a match of Co-op only he would load into the match and I would get error code 216. If I were the party leader and I started a match of Co-op I would load into the match but John would receive error code 216. Whenever I play solo on any multiplayer game mode I don't get error code 216, same goes for John. we are both using wired connection and ping site is Japan (79ms). speeds are 500/130. we have tried to switch to wireless and the problem persists. tried resetting the modem and routers and the problem is still there. The problem only started recently about 1 week ago. before that we had no connection problems whatsoever whether it was playing solo or in a party together.