Diagnosis
You see this message in one of the following situations:
You want to allocate the BOM for the material you entered on theinitial screen to an additional plant.
You want to allocate a configured material to one or more BOMs for theconfigurable material.
You chose function New allocations. You can only create thisallocation for the (configured) material that you entered on theinitial screen.

Procedure
Please correct your entry in the field Material.
You can create additional allocations for the selected (configured)material. For example, you can allocate the (configured) material tothe BOM for the configurable material in another plant.
Note on 2.)
If you want to allocate other configured materials to the BOM for theconfigurable material, you have to create an allocation for eachconfigured material separately (Material BOM -> Alloc. config. mat.-> Create).