If you equip the Minecon 2011 Steve skin from the Minecon 2016 skin pack and also equip the Founders' cape at the same time your Elytra becomes invisible.

Here's a video demonstrating how the bug is reproduced: https://www.youtube.com/watch?v=UJcst9Cfzd0

This bug also applies to every other cape from the Minecon 2016 skin pack.

PS: Please add elytra textures to the previous Minecon capes on Bedrock Edition <3