Gamemode other than Spectator in Debug world
Mod note
The debug world is only for observing how all the blocks in all their possible states render, generally for testing resource packs. You're only supposed to be in spectator mode in the debug world.
So:
Take note of the 2000 entities, this is caused by me walking into and through (continuously) some golden pressure plates. I'm assuming this is relevant to a block update or something which is getting triggered, its thinking it should break the plate but it's being put back by the protection?
Not sure exactly, i'm sure you know what it is - but it's making a hell lot of entities drop as well as a horrific sound generally meaning crash and world has to be deleted.