How To Fix M8787 - & & not copied (Moving av. price for material & would be negative)

M8787 - Overview

• Message type: E = Error

• Message class: M8 - Invoice Verification/Valuation

• Message number: 787

• Message text: & & not copied (Moving av. price for material & would be negative)

What causes this issue?

Purchase order &V1&, item &V2& is not copied over to the document,
since posting this item would lead to a negative moving average price
for material &V3&.

System Response

The system does not permit a negative moving average price.

How to fix this error?

Check your entry in the field <LS>Amount</>.
If your entry was wrong, acknowledge the next message. From the
document overview screen choose <LS>Goto -> Open order item</>. A list
appears of items that were not copied over. At the end of the list you
will find purchase order &V1&, item &V2& and the amount you entered.
Correct this amount.
If the amount you entered was correct, take a look at:
the stock value of the material by choosing
( Environment -> Master data info -> Display material)
the posting history by choosing
(Environment -> Line items -> By material).
You may have to reverse postings that were made in the past (for
example, because goods receipts were wrongly valuated or price changes
were made wrongly) before you carry out the current posting.

Error message extract from SAP system. Copyright SAP SE.

M8787 - Details

• The SAP error message M8787 indicates that there is an issue with the moving average price (MAP) for a material. Specifically, the error states that the moving average price for the material would be negative, which is not allowed in SAP. This typically occurs during inventory management processes, such as goods movements, when the system attempts to calculate the moving average price based on the current stock and the value of the goods being moved.
  
  Cause:
  
  
  Negative Stock: The most common cause of this error is that the system is trying to process a transaction that would result in a negative stock level for the material. This can happen if you are trying to post a goods issue or a transfer that exceeds the available stock.
  
  
  Incorrect Valuation: If the valuation of the material is incorrect or if there are inconsistencies in the material master data, it can lead to a situation where