Diagnosis
You want to allocate the BOM to plant &V4&.
The BOM contains material item &V2& &V3&, which has unit of measureV1.
However, this unit of measure is different from the stockkeeping unitor unit of issue in material master &V3& in plant &V4& and cannot beconverted into either of these units.

Procedure
You can only allocate the BOM to plant &V4& if the units of measure areeither identical or can be converted to each other.