When opening world, you get teleported high up in the sky

Sometimes when you relog into your world. A message appears "Your home bed was missing or obstructed" and you appear high above the clouds and you fall to your death
Edited.
Okay, I was in a FLAT world when that happened. Nothing above me. When I logged out, I was standing near a chest. When I logged back in, this message appears "Your home bed was missing or obstructed", but instead of near the chest I appear high above the clouds and then I fall to my death.