Interface variable of basic rule type does not exist

What causes this issue?

Variable &V4& was specified for basic rule &V2& (rule type &V1&, call
number &V3&) in the assignment of the variables of the attribute
normalizing rule to the variables of the basic rules. This basic rule
type does not exist.

System Response

The attribute normalizing rule is inconsistent and cannot be executed.

How to fix this error?

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

Procedure for System Administrators

Correct the attribute normalizing rule.

Error message extract from SAP system. Copyright SAP SE.