Diagnosis
The given difference quantity is larger than the default. This largerquantity can only be correct in one specific case.

System Response
You can execute the following return postings for an inbound deliveryitem:
Quantity cancellation with material document (for example, withmovement type 102).
Return delivery without creating an outbound delivery (materialdocument is generated, for example, with movement type 122).
Return delivery with outbound delivery. When the outbound delivery isposted as a goods issue, the material document is created (for example,with movement type 122).
The quantity proposed for the return posting takes into account all thereturn postings mentioned above. Whether the outbound delivery has notyet been posted as a goods receipt, has been posted as a goods receiptor has been cencelled is of no importance in the determination of theproposed quantity.
If a larger difference quantity is entered, this is correct in thefollowing case:
One or more outbound deliveries have been created and posted for goodsissue for this inbound delivery item and one or more of these postingshave or will be cancelled and so a return posting quantity is required.

Procedure
Check whether this is the case.