Shopify would not accept stock at the inventory location Shuttle uses, so the transfer or update stopped. Nothing was created or changed in Shopify for this product.
Why Shopify refused the Shopify inventory location
Shuttle sets stock in Shopify at the location chosen in Default Shopify location. Shopify refuses that location in these cases:
The location was deleted or deactivated in Shopify after you picked it.
The location belongs to a fulfillment app, such as a print-on-demand service. These apps do not let other apps set stock at their locations.
The product already exists in Shopify, and its variants are not stocked at that location.
How to fix a refused Shopify inventory location
Go to Settings > Products > General and find Shopify inventory location.
Click Refresh locations to load your current Shopify locations.
In Default Shopify location, choose a location you manage yourself, not one added by a fulfillment app. Locations marked (Inactive) cannot be selected.
Click Save.
If the product already exists in Shopify, open it in Shopify and make sure each of its variants is stocked at that location.
The Default Shopify location applies to all your products and to stock syncing. Pick the location where you keep most of your stock.
If Shuttle shows Only one location, it uses that location for every product. Make sure the location is active in Shopify and is not run by a fulfillment app, then click Refresh locations.
Do automatic transfers of new Etsy listings start again?
Yes. Automatic transfers of new Etsy listings to Shopify start again on their own. While the Default Shopify location is missing or inactive, Shuttle holds back those transfers. Once you select an active location, new listings transfer again without anything else from you.
Transfer or update the product again
After you fix the location, run the product again from Products on the Etsy → Shopify tab:
If the product is not in Shopify yet, click Transfer to Shopify.
If the product is already in Shopify, click Update in Shopify.
To find every product that failed with this error, check Transfer History.