I played in a Singleplayer Flatland World and used the /kill command. After doing that I couldn't move after respawning and my camera was stuck inside my skin.. And after reentering the world I instantly died again and the camera is just completley broken. When I pressed F5 my skin was invisible but after reentering the world it was again visible.

And as seen in the first and second Picture Chunks stop loading correctly

But you can still access the chat and use commands to move around.

Similar to this one: https://bugs.mojang.com/browse/MC-176004