IDoc transfer: First record is not an IDoc control record

What causes this issue?

The first record transferred must always be a control record. The first
10 letters of a transferred control record are 'EDI_DC '.

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

Data stream: &v1&

System Response

How to fix this error?

If the error keeps occurring, activate the CPI-C trace functionality.

Error message extract from SAP system. Copyright SAP SE.