Dear mojang i go to the end to beat the dragon and then i died thankful I set my spawn and then i back to the end but the dragon is gone and the Dragon health barr is gone to after i searching for the Dragon I got hit by him but I cannot see but i still can his voice and when i hear him in the middle i explode like 6 bed and he is still not died I'm trying to hit with my sword but i don't hear any damage from the dragon and i think he is invincible and i stuck in the end with a invisible and invincible dragon and then i turn to creative mode to see what happent but it didn't do anything and while in survival mode i found an obsidian pillars without bedrock and end crystal and then my survival world cannot achieve an achievement and then I'm spawning another dragon and kill it and then the portal turn on but the invisible dragon is still alive

So please fix the bug dear mojang