Number range sub-object &/& has not been defined -> error code: &

What causes this issue?

The number range sub-object has not been defined for the CO-PA segment
numbers. This error is documented online in function module
NUMBER_RANGE _INTERVAL_UPDATE, parameter ERROR.

System Response

Generating has been terminated.

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.

Error message extract from SAP system. Copyright SAP SE.