The batch has not been classified

What causes this issue?

You have created a batch in the background or in batch input mode.
The system has not automatically classified the batch.

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?

If you want to classify a batch in the background or in batch input
mode, you must define this explicitly in the corresponding session;
that is, you must call up classification from the screen
containing general batch data using F07 (classification).

Error message extract from SAP system. Copyright SAP SE.