i have a problem for posting GRN with reference to subcontracting challan. while refering the subcontracting challan in GRN process, it gives error "challan material is differ from material doc".howver i can able to post the other line item for same purchase order . for my observation , the challan number issue material and challan material is correct. i could not findout where is the problem . please help me to solve this issue.