NAST object key not filled correctly (internal error)

What causes this issue?

You wanted to read a trading contract.
In this process, the system filters the number of the trading contract
from the object key of a NAST record. A check found that the number of
the trading contract does not have a valid value.

System Response

INCLUDE ISR_STOP

How to fix this error?

INCLUDE ISR_VERWALTUNG

Procedure for System Administrators

An internal error occurred in function module &V2&. The object key of
the NAST record has the following value: &V1&.

Error message extract from SAP system. Copyright SAP SE.