Diagnosis
The assignment of &V1& to a program position is designated as arequired entry in the screen layout control in Customizing.
However, if you delete the assignment here, this does not guarantee asubsequent assignment of &V1& to a different program position.

System Response
Therefore deleting the assignment to the program position is notallowed here.

Procedure
Delete the assignment in master data maintenance of &V1&, and thenenter a new assignment to another program position there immediately.