Format mapping must contain at least one node with defined output field

What causes this issue?

No output field has been defined for any of the field nodes in the
format mapping.

System Response

The system can process input data, however, it does not know where to
place that in the output structure, thus, it cannot generate any output
data.

How to fix this error?

Ensure that your format mapping contains at least one field node that
has an output field specified in the <LS>Output Specification</> section
of the node. Note that a field node must be a child node of either a
record, a field group, or another field node.

Procedure for System Administrators

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.