I've faced this problem myself and I guess this is your problem:
Let's say you want to give a user (systemuser) read access to an account through an access team. You create an access team template with read privilege and attach it in a grid to the account form. When you try to add a user which has no account read privilege
in its roles, you'll get that error.
I propose you give the user's role account read privilege (user level for example).
Recap: when you add a user to an entity's access team, that user needs to have a role with the same privileges on that entity (user level at least) as those granted by the access team.
Good luck,
Israel