Worlds that are created in unity 5.3.4p1 won't even download. You just get stuck at 0B/0B and have to return to home.
Here are some examples.
wld_c95b8313-8607-4437-a808-57bd86eef5a1
wld_b4fc88e5-d4d9-4452-a620-6b2ba0429fb1
wld_97fda4a1-f820-4f09-a88c-2d2a95b668f7
wrld_a7663a32-e98d-48eb-b5c2-fd50c2e373c3