Custom world won’t load

I downloaded @Rflong7 Haunted Valley for some fun ghost hunting, but it just gets stuck on the world loading screen. It isn’t frozen because they images and text change as it loads. The green bar goes to the very end, with like 1/2cm of grey bar, and just sits there.

Ive made sure I’ve had all required packs for this world, installed it through origin. Any ideas?