Greetings @Seller_0fbMUANiznzCZ,

In general I'm not able to assist with issues with Printful and you will need to work with Printful to resolve this issue but it looks like the error is related to your restrictions in creating products for this Brand. Have you reached out to Seller Support or requested approval to sell this Brand? If so can you please provide the Case IDs so I can review and see what options I can provide? Thank you.

-Glenn