SAP Message WTADDI455 - Line cannot be deleted: see long text

Diagnosis
You want to delete anadditional duringsubsequent processing for apromotion.
Materials are still assigned to the additional in question; linecannot, therefore, be deleted.

System Response
The line with the entry for the additional is not deleted.

Procedure
If you want to delete the line, check the assignments of classes,materials, and units of measure. Only when no more assignments existcan the line containing the additional be deleted.

Hints
Your system checks the assignments for all materials, not onlyfor those which you selected. It may be the case that all selectionsfor the current materials have been deleted but assignments may stillexist for materials which have not been selected at present. In thissituation, the assignment has also not been deleted.
Check that you selected all materials in the initial screen.