Item category and Account assignment category field grayed out in PR/PO
While making a PR/PO we use both the item category and account assignment category. However, after saving the PR/PO, when i try to change the fields through ME22N/ME52N, the fields are greyed out. I dont think this can be controlled through the layout screen.
Is there anyway the fields can be made modifiable in ME22N/ME52N ?