Document conditions missing (internal error)

What causes this issue?

While the system was checking the customer billing documents
(settlement documents) created via the general billing interface, the
document conditions that should exist were not found.

System Response

The system recognizes a situation of data inconsistency and does not
perform the requested function.

How to fix this error?

Contact your system administrator. There is probably an error in the
program.
The rebate arrangement concerned is &V1&.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.