SAP Message UPS524 - Packet type &1 is already used in distribution units

Diagnosis
You want to delete package type &V1&. The package type, however, isalready used in the units.

System Response
The package type cannot be deleted.

Procedure
Proceed as follows:
Delete the units in which the package type is used. You can only dothis if the units have not been released.
Delete package type &V1&.