I'm also having the same problem with a mandatory design. I'm on Neil's route and need a mid-length skirt, also with gingham pattern (chapter 4 I think). I'm wondering if there's a way we could change/"predict" which design is required. I really want to see the next chapters, thanks!
Hi there, as with the post above you; make sure the pattern has the right colour. It is easy to mistake the pattern colour with the base colour when the pattern has squares or stripes. So if the design isn't being accepted, swap the pattern colour and the base colour.
You can follow Neil's walkthrough here: