If using a FULL Category template then I would suggest
- Download the latest one
- Don’t Mess with any of the column headers
- Use Partial Update
- Just fill in Product Type, Seller SKU, Update Delete, Handling Time columns
- Test with 1 SKU to make sure it works as you expect before doing them all
,
The link above talks about the Price & Qty template that also updates ASIN Level Handling times