Blocked by gating
Solution: It’s in a restricted category for your seller account and you can’t sell it. You can request approval by adding it manually here (Link will direct you to Seller Central). After that, you can add it again. If you still have the same error and you can add it manually on Amazon seller central, then it is an Amazon API issue. You can try to add this item tomorrow.
**You will not need to create a new sku for the Asin but rather Amazon granting approval to sell the category, brand or item is enough to resolve the error.