Scenario

Using UPS, if some Shipping Items are not listed on web store checkout and those missing items when selected and calculated on a sales order prompt "Could not calculate the cost for the selected Real-time rate. UPS did not return any rates for the specified origin and destination addresses"

Solution

1. Navigate to Setup > Accounting > Shipping
2. Under the Preferences tab and Default Package Type portlet, select Your Packaging on UPS Packaging Field
3. Click Save