Had the same error. Also happened whenever a button was pressed.
I had this bug too, It was a single player world and I flew into an unloaded chunk and after that, I couldn't land. I assumed it was because I added feather falling
try falling off the island in the end maybe? or does the void below not count as the Void biome?
(also, try the biome that you go to after defeating the dragon)
the "ignored non-lowercase namespace" seems to be a common error. Currently looking for a fix myself. Will post if/when I find a solution.