About Domain Local Groups

Domain local groups (DLGs) cannot be used in a mixed-mode domain. If you use DLGs to define role permissions, when group members attempt to access secured content, those group members might see "access denied" error messages.

This problem can occur if your domain is operating in mixed mode. In mixed mode, the scope of a DLG is limited to the domain controllers only. The DLG is not valid for member servers. The DLG can still appear valid as certain applications, such as SharePoint Portal Server resources, do not filter out invalid DLG entries.

If you grant the necessary role permissions to the domain user accounts individually, those users can gain access to the secured content, but this approach nullifies one of the advantages of using DLGs.