(Invalid or Duplicate SKU; Invalid or Duplicate ID)
The “Invalid or Duplicate SKU” error in WooCommerce is typically caused by a product being assigned an SKU (stock keeping unit) that already exists in the system and that is assigned to another product. This can occur when attempting to import products, add new products manually, or make changes to existing products.
Here are some steps you can take to troubleshoot and resolve this error:
Check your product data: Make sure that all of the products you’re attempting to list or edit have unique SKUs. If you find any duplicates, change them to something unique before trying the publication again.
Check on your WooCommerce: SKUs have to be unique and not already in use by other products in your store. When the error is returned, copy the SKU code of the product in error and check on your WooCommerce store to find the product already associated with that SKU.
Check for variations: If you’re using product variations, make sure that the SKUs for each variation are also unique.