There is no valid form

What causes this issue?

During the printing of barcodes, the system could not find a valid
form. Either no form was selected, or the form selected is not active.

System Response

The print procedure terminates.

How to fix this error?

Use a valid form. You can either use the sample supplied by SAP, or
modify it to your requirements. You maintain forms using the "form
painter" (SE71) transaction.

Error message extract from SAP system. Copyright SAP SE.