I am trying to list a generic product but every time I get to the "Offer" page and select that I will ship the item myself, a popup appears that reads:

ERROR: Changes to this product detail page are not allowed. If you want to sell a generic product, you must create a new product. To create a new product, follow the process outlined in Add a Product tool. For more information, go to Amazon Generic Product Policy.

I've attached an image of the error as well.

I have created new products countless times and get this error every single time, I have no idea what to do - does anyone have experience with this and know what I may be doing wrong?

I got approved by Amazon Handmade a couple months ago but have been having issue after issue trying to list my first product - any guidance is greatly appreciated.

Thanks in advance!