If you go into the Nether in 17w06a youre Armorbar is gone. If you put a piece of Armor off youre Armorbar returns.

Put the summary of the bug you're having here

What I expected to happen was...:
You should see youre Armorbar when you go into the Nether

What actually happened was...:
I went to the Nether to get some Blazerods. Then I saw that my Armorbar wasn´t there. I thought didn´t i took Diamondarmor to the Nether and looked in my Inventory. Then I saw that I had my Diamondarmor on. I put my chestplate off. My Armorbar returned. I put it again on. My Armorbar was still there.

Steps to Reproduce:
1. Go into the Nether in Survival with Armor
2. You will see that there is no Armorbar
3. Put off a Piece off Armor. You will see that youre Armorbar is back.