If you get a minute would you mind testing this again for me? I may have found the problem with the shader.
For the time being you can just hit CTRL + G to jump to that world.
I could navigate the place now, it worked for the most part! There's a few objects that are still a solid, unshaded pink, though:
... and the WISE letters in the secret area. But otherwise, I managed to navigate my way around the place this time!