Why can't I fly with the elytra in Minecraft 1.9?

I just downloaded the new update for Minecraft 1.9, equipped the elytra, but can't fly. I'm currently running vanilla 1.9 and have tried everything to fly. Anyone else experiencing this or know how to help?

You have to jump (originally set to spacebar) in midair

You didn't plug the pig up to the hydrocensor under the illusion core. Also try running the quad censor cable to the double graphics hardware card.

The elytra does not allow you to fly, it allows you to glide. Jump off of an ledge and look down and then up.

You have to walk off of something tall, look forwards if you want to go straight and then space bar.

It won't work I did everyone's advice but still no.

You need to hold down the space bar when you fly/glide

I'm pressing space in midair but it dosent want to glide D;

Do you hold or press the spacebar?