Diagnosis
Unassignable nodes are nodes which refer to a sibling node which isnot/no longer in the structure. Unassignable nodes are usually nodeswith an enhancement ID which refers to a sibling node without anenhancement ID. This sibling node has probably been deleted.

System Response
The system can no longer uniquely determine where the unassignablenodes are to be displayed, so they are displayed as the last nodes attheir level.

Procedure
Reassign unassigned nodes. Contact the person responsible for theenhancement ID if necessary.
You can find unassignable nodes in the structure with the 'Position onUnassignable Nodes' function.