Diagnosis
The 'flat-rate install.' indicator was changed in period &v2& -- &v3&for installation &V1&. This is either the billing period or the budgetbilling period.

System Response
Billing is cancelled because the billing program does not allow the'flat-rate install.' indicator to be changed.

Procedure
Maintain the indicator in the installation so that its consistency isalways ensured within the billing period (or budget billing period).