Error "Lot Is In Use" when perform Item Reclassification

Hi Expert,

I get the error message.
“Lot Is In Use”
CAUSE: This lot is in use by another work order
RESOLUTION: . . . Use a different lot
when performing item reclassification. I have checked the item availability; everything is fulfilled. I have checked the lot master; the WO number is also empty. But the error is still there. What causes this error, and how can I solve this problem cause I need to use the item with the specific lot number?
Maybe someone here has experienced the same issue. Thank you.