Diagnosis
When a task group is assigned to a different task group or role, thesystem determines whether the object to be assigned (which can alsocontain other objects) triggers recursion.
This is the case if creating the relationship leads to the same taskgroup occurring more than once in a hierarchical structure.

System Response
The system prevents you from creating the relationship.

Procedure
Make sure that the object to be assigned, and/or its hierarchicallysubordinate objects, do not occur in the object hierarchy currentlybeing processed.