my son's xbox one to play halo 5

My son’s account cannot play halo 5 guardians even if I his dad created an account so I can manage permissions. I keep getting sorry message and some stupid number, so I cannot sign in to give permission, can some one hlep.

1: is the error message specifically saying that it has to do with permission?

2: Has this account been used to Play Halo 5 before, or is this the first time?