Diagnosis
The installation group characteristics of secondary installation &v1&must not change in the period &v2& to &v3&. Thegrouping type of the corresponding primaryinstallation &v4& must also remain the same in this period.

System Response
The billing of installation &v1& is cancelled.

Procedure
Try not to change the installation group characteristics of primaryinstallations. If you do, you must bill all secondary installations upto the date when the changes were made.