Items/Mobs/Players Invisible

Every block and mob, including own player model / other player models(every camera angle) are invisible in both single player and multiplayer. Only things visible through testing so far are particles, paintings, item hitbox, and the hopper in a hopper minecart. Actual GUI (inventory/exp/hotbar/etc. are unaffected by this bug). Problems are existent regardless of texture pack (default or custom).