FarApp uses Amazon’s flat file templates for syncing items to Amazon. Starting January 31, 2019, if you are using category specific templates or the Book Loader, Amazon will no longer accept older versions of the category-specific inventory templates.
You will need to create a custom template to list different types of products across multiple categories using one template.
To list products using the new inventory templates:
1. Log in to Seller Central.
2. Under the "Inventory" tab, go to "Add Products via Upload (https://sellercentral.amazon.com/listing).
3. On the "Download an Inventory File" tab, using the Search tool or Product Classifier, select the types of products that you want to list.
4. Select your template type under "STEP 2: SELECT THE TYPE OF TEMPLATE."
5. Click "Generate Template" to download your new template.
6. Provide FarApp with your new file by opening up a support ticket, here.
To learn more about how to generate the customized template, see Create your inventory file template: https://sellercentral.amazon.com/gp/help/202094740.