The most common culprit to this issue is what location the inventory is stored in. Assuming you have more than one location, I suspect that you created shipping rates for only one of your locations and not all of your locations. If the inventory for the product(s) is set to the location that doesn’t have shipping rates, then the error you’re seeing will appear.
You can either create shipping rates for the missing location or transfer the inventory to the location that has shipping rates. Either route should resolve the issue.
Are your products supplied through an app? Such as Oberlo, or a Print on Demand app? If yes, those setup locations within your shipping area. If you set up rates for your home location, but not the app location then that could also cause the error. You can confirm this by checking Settings/Locations and your shipping rates:
You’ll notice that the shipping zone/rates only apply to 2 of the 3 location apps. If any of the app locations are missing and the product inventory is connected to that app, then this would explain the error.
If that’s not it, then this would require a closer look at your account.
While we’re not able to provide account-specific support via the Shopify Community at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit https://bit.ly/3cJkx8V and log in to your account to create a support request.
Since this is the next step I’ve marked this reply as the solution for the benefit of others who may discover this topic. Thanks!
This is not an accepted solution as i do not use any apps at all for shipping just the standard Shopify system. I have triple checked everything with your system still not working. I there someone i can contact at shopify to look into a fix please?