Error in HU Proposal

hi friends,

while creating HU Proposal (T.code HU02) manually,

i came across with following error:

Material not found amongst the materials to be packed

Message no. VHUPD010

Diagnosis:

Material is to be packed according to the packing proposal. This material was not specified as a material to be packed.

System Response:

The packing proposal was not accepted.

Procedure:

Replace the material in the packing proposal with a material that is to be packed.

please help me

with regards