Document & cannot be changed, cancelled, or copied

What causes this issue?

The document you entered has been transferred from the SAP System. The
document lines are not complete. Therefore, it is not possible to
change, cancel, or copy this document.

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?

Enter the reversal movement type without document reference.

Error message extract from SAP system. Copyright SAP SE.