"Cannot find variant" for digital download

I’ve just added a second digital download product to our website (we’re using the Dawn template). I used the Digital Download app to upload the files, create a “download ready” email, and went to test the product in preview mode. I’m getting a “cannot find variant” error both in draft and active mode for this product.

I’ve deleted and reloaded all of the files. There aren’t any variants for this digital product. I don’t understand what this error means. Can anyone help me troubleshoot?

I’ve seen several of these questions and I havent seen anyone respond. Does someone know how to fix this error?