System.Data.Entity.Core.EntityException
How to solve
The navigation property 'Users' on entity of type 'System.Data.Entity.DynamicProxies.Roster_15E7C2C14DF3BFAC9EE5D67288C206B1942EC1A906CA6FEAECA11962C' must implement ICollection<T> in order for Entity Framework to be able to track changes in collection