Flying mobs and players are not visible above build limit y 255. This can be seen in Grians latest Hermitcraft video fighting a wither using a elytra. Wither can go above 255 and become impossible to hit. However this does not seem to affect the ender dragon.
To Recreate summon a wither and fight it using a elytra
He does this at the beginning so no reason for a time stamp.
Thank you for your report!
However, this issue is Invalid.
Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.
Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.
Any plugin issues need to be addressed to the creator of the plugin or resource pack.
If you have problems on large servers, such as The Hive and Hypixel, please contact them first as they run modified server software.
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