Unable to respawn the Ender Dragon. I have tried multiple methods found here including removing a bedrock block in creative prior to placing an obsidion block and ender crystal. I have also tried placing the ender crystals on various pieces of bedrock around the portal to no avail. The world was generated early on (~1.8ish) and the dragon was killed. I went on a Minecraft haitus and began playing again in 1.10.2. I have tried the 1.10.2 and 16w38a versions. Review of level.dat indicates no ExitPortalLocation. I have attached the level.dat. Thank you.