Variable key for main condition record missing (internal error)

What causes this issue?

The system requires the associated main condition record for a period
condition record (internal number: &V1&). This main condition record
does not exist.
The affected rebate arrangement has the number &V2& (may be missing).
The error occurred in function module &V3&.
The error may be due to one of the following reasons:
Faulty call of function module with invalid or inconsistent data
Database error (i.e. the database table VAKE does not contain the
condition record)

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?

Contact your system administrator.

Error message extract from SAP system. Copyright SAP SE.