It is these brushes in particular. https://gumroad.com/l/yFKMw
There doesn't appear to be anything different about them from normal photoshop brushes that can work just fine with Affinity. Normally when I install anything of substance it might cause Affinity to freeze for a second before starting to work again. When I go to install these it just freezes permanently. I've given it up to four hours to start working again, but it always results in crashing instead. And I do say Affinity because I have tried installing the brushes on all three platforms with the same results. I have tried drag and dropping them in to install as well as the usual import brushes option. The brush pack is only 53 mb. How can I install these brushes without causing a crash? Or if it can't be done, why? I'd like to know so I don't purchase unusable brushes in the future.