EDI: Sender partner number in control record is default

What causes this issue?

An error was identified in the control record while adding an
<DS:GLOS.IDoc>IDoc</>. No value has been entered for the sender partner
number, which is not permitted.

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?

Please inform your system administrator.

Error message extract from SAP system. Copyright SAP SE.