Reference material has not been classified

I am getting following error when I try to send a material variant from ECC to APO in CFM2.

"Reference material has not been classified"

Configurable material X is populated used in MRP3 view of material master of material variant V.

Class Y (Class type 300) is used in classification view of configurable material.

Characteristic values not populated in classification view of configurable material.

Class Y with class type 400 exists in APO.

Conifgurable material is in APO and has CDP class Y populated in product master.

Now, when I try to activate the integration model to send material variant V in CFM2, .I am getting following error message.

"Reference material has not been classified".

We are using ECC6.0 andSCM 7.0.

Can anybody help me out?

Thanks,

Srini