Still an issue in late 2025. Thanks for the heads-up that the second-last stage gives the correct dough (I didn't notice on my own first attempt).

For anyone else who lands on this post and wants to make use of the failed mixture, I did something like... in a new bowl, add 500g biscuit crumbs, 300g butter, mix with hook machine. Add fail-mixture and two full bars of dark chocolate, mix with paddle machine. Viola, usable dough for cakes and cupcakes. Basically, fail-mix + flour equivalent + butter type thing = dough, and it's optional if you want to add around 400g of whatever flavoring ingredient you want for a hashtag.