Diagnosis
You changed the meter reading unit from &v1& to &v2& for the contract.You made this change within a period-end billing period. However, youare not permitted to change the meter reading unit within a period-endbilling period.

Procedure
Ensure that the meter reading unit does not change within theperiod-end billing period. The current period-end billing periodstarted on &v3&. If you wish to allocate the contract to a differentmeter reading unit, you can do this after the end of the period-endbilling period.