when calling GetPrimaryKeyFieldsFor function

[progsherief]

dear,
exception While trying to use context.UpdateGraph
ex: context.UpdateGraph(UpdatedWF, map => map.OwnedCollection(x => x.contexts));
i have this error : ambiguos match found - when calling :GetPrimaryKeyFieldsFor function at
return metadata.KeyMembers
.Select(k => entityType.GetProperty(k.Name, BindingFlags.Instance | BindingFlags.NonPublic BindingFlags.Public))
.ToList();
line