Gr with ref to SC Challan

hi guys

1.Sub Con PO craeted

2.MB1B 541 goods transferd with ref to PO

3. J1if01 with ref to Mat doc

4. GR MB01with ref to PO

its shwoing one dialog box

where 2 tabs 1 is excise invoice & 2nd is sub con challan

in sub con challan tab

when am entering SC challan number & year

its showing error as

Challan material is different from material document

Message no. 8I572

am not enetring any thing in excise invoice tab

can any clarify me

thanks

nani