I was playing on a superflat world, tried to find an end city so after teleporting to the outer end i used the /locate EndCity command. After that chat and commands stopped working, when i jumped into the void even at Y=-3000 nothing happened, the world couldn't save and the only way to turn off minecraft was the task manager. Played a little bit with the exploit an ddiscovered, that elytra also glitches out after typing the command.