SAP Message V1479 - Schedule line categ.for schedule line &1 &2 cannot be determined

Diagnosis
The schedule line category cannot be determined.

Procedure
Check the entries for the schedule line category determination for therelevant item category and add to them, if necessary.
INCLUDE 'NA_CUST_MAINTAIN_3' OBJECT DOKU ID TX LANGUAGE E
IF &DEVICE&='SCREEN'
Proceed
ENDIF