even after the patch, my player object still disappears when hitting the crab from the left. trampoline and all the other goodies work, but that one is still there for me. that is until i install the Part 13 Patches, and something in those fixed the bug. if you're having a hard time figuring this one out, after you add these patches in the video, go ahead and add the ones in part 13 and they should be fixed.
At 15:30 joe mentions the stopOnSolid_Platformer_prizeBlock is in MOD_Platformer/reactions, but we put that in Base4_5/AI reactions like he mentions it should be. took a second to find it when i knew i moved it over from the patch file.