Sometimes, when you try to create a devproduct via the creator hub, it will result in the error in the title, and thus, you aren’t redirected back to the devproducts list.
Note that this does create the product, the error that appears isn’t actually preventing the product from being created, however it is a bit annoying to have to manually click “back to developer products” to return to that page.
It seems to happen almost at random, and nothing special has to be done to get it to happen, just try creating a few devproducts and it will occur.
A video of it happening, a devproduct with the name “testa” does not exist under the game prior to this:
Page URL: https://create.roblox.com/dashboard/creations/experiences/5186594860/developer-products/create