What does No menu item for this barcode mean?

No menu item for this barcode. means the code you scanned did not match any product. Sidro checks Barcodes first, then the Item code (SKU).

1. On the web, open Catalog and edit the product.
2. Check the code under Barcodes (optional). If it is missing, click Add barcode, type it, and click Save.
3. Make sure Active (visible in POS) is ticked.
4. Scan again on Point of Sale.

"This item is out of stock." means the product was found but its stock is 0. Receive or adjust stock in Inventory, or check the out-of-stock settings in Settings, Inventory.