Panthom Assembly: Not possible to explode the panthom assembly

Hi All,

During creation of planned order for a material i am facing the below problem.

It was not possible to explode the panthom assembly

The material is Assembly material and it has multiple BOM.

Could any one kindly explain the reason for the above problem and solution for the same. As per our analysis it problem nay be because of Validity of some of the BOM expired. Any way dont know the exact reason.

Thanks In Advance

Karthick