This error occurs when the product you're trying to publish on Etsy has already been removed. To resolve this, follow these steps:
- Go to the All Products section and search for the product showing this error.
- Select the product, and from the Bulk Action dropdown, choose 'Unlink listing on app', then click Action.
- After unlinking, select the product again, choose 'Publish on Etsy' from the Bulk Action dropdown, then click Action.
This will re-upload the product to Etsy.