Diagnosis
You want to hang group &V1& under group &V2&. However, both groups alsoexist in other hierarchies. If you carried out this change, group &V2&would exist in at least one of these alternative hierarchies more thanonce.

System Response
You cannot make this hierarchy change.

Procedure
Check which hierarchies contain groups &V1& and &V2& (using thewhere-used list). Change the hierarchies you find so that the change youwant to make to the current hierarchy is then possible.