Amazon has special (not well explained) rules regarding use of a Brand's name and or if you are a Brand-Registered Company.
Below are two examples of this branding error message.
1: Brand Name Error
This means you're attempting to use a bar code number on brand name item, but this brand has it's own barcodes and the one your attempting to use/assign does not match that brand. Example: You're listing a Nike shoe but trying to use your own barcode, this will not work since your barcode is different then Nike's own barcode numbers.
The solution or "work-around" to this is to not input the brand's name (ex: Nike) in the brand field, but instead input your DBA or amazon company name in the brand field instead and then input the brand's name (ex: Nike) in the item description. There is no other way to make it work, as the moment you type "Nike" into the brand field amazon's automated system cross references Nike's own barcode numbers against the one's you're trying to enter.
Amazon does not make public any list of brand's that it does this for/to.
2: Brand-Registered Seller Program
This is a very similar error message as #1 and has a similar theme. You would see this message if you are doing the above error or if your amazon company is or has become "brand registered".
As of the beginning of 2018 (around march) we found out that amazon had changed their rules for brand-registered companies and are now forcing all of these companies to rent their GTIN's from GS1 directly going forward.
The solution for this is to go to GS1 and rent a separate block of barcodes just for these "brand registered" listings, there is no work-around or other option to use GTIN's that you own outright. It is our experience that amazon made past listings grandfathered, so it is only affecting new listings.