Error Code 8541-8542
This error is often called a single match error and occurs when your Product ID type (UPC, EAN, JAN, ISBN, etc.) is equal to the Product ID of an existing ASIN.
Some of the information you’re submitting contradicts the product information (title, brand, color, size, etc.) that is already present for that particular ASIN.
The solution is to use fast-listing soft; the purpose of fast listing is to send only product ID, price and quantity.
1- Click three-dots and select “fast listing state>fast listing”.
2- Click the “Advanced Sync Options>Delete&Recreate”
3- Sync the channel from the top left.