Stock level shortfall for item &

What causes this issue?

For item &V1&, the quantity entered exceeds the warehouse stock on
hand.

System Response

The situation outlined above is not allowed.

How to fix this error?

Check the current stock level ("Stock" column") and the actual quantity
in the stockkeeping unit ("Quantity Un" column), and correct the
quantity entered in the unit of entry ("Quantity in UnE" column).

Error message extract from SAP system. Copyright SAP SE.