How To Fix AH778 - Not possible to change the rate category

AH778 - Overview

• Message type: E = Error

• Message class: AH - IS-U billing (master data)

• Message number: 778

• Message text: Not possible to change the rate category

What causes this issue?

You changed the rate category for installation &v1& on &v2&.
Backbilling has been established for this installation. The current
backbilling period starts on &v3&. You are not permitted to change the
rate category within the current backbilling period.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If you wish to change the rate category, you can do so at the start of
the next backbilling period. You can end the backbilling period early
by executing a final billing.

Error message extract from SAP system. Copyright SAP SE.

AH778 - Details

• The SAP error message AH778, which states "Not possible to change the rate category," typically occurs in the context of SAP's Controlling (CO) module, particularly when dealing with internal orders, cost centers, or other cost objects. This error usually arises when there is an attempt to change the rate category of a cost object that is already in use or has been posted to.
  Causes:
  
  Existing Transactions: The rate category may be locked because there are existing transactions or postings associated with the cost object.
  Status of the Cost Object: The cost object may be in a status that does not allow changes to the rate category (e.g., it may be closed or settled).
  Configuration Settings: The system configuration may restrict changes to the rate category under certain conditions.
  Authorization Issues: The user may not have the necessary authorizations to make changes to the rate category.
  
  Solutions:
  
  Check for Existing Transactions: Review the cost object for any