Confirmed for 1.9.1-pre3.
Confirmed for 16w02a.
Confirmed for 16w02a.
Confirmed for 15w51b.
I've tested this with water/lava buckets, snowballs/eggs/ender pearls, and all boats.
When I deleted the usercache.json file, I couldn't log in as the launcher froze when I pressed the "Log In" button. I decided to copy the "authenticationDatabase" object from the backup to the usercache.json file, and I could log in, however I couldn't press the "Play" button as shown in the screenshot.
dammit 20,000 character limit
This is works as intended.
The Elytra shouldn't go invisible, like all other armour pieces in the game. You are proposing that it should.
Works as intended.
The Elytra is not supposed to go invisible along with the player, just like other pieces of armour. This is bug MC-90095.
Confirmed for 15w51b.
Incomplete without the full crash report.
Confirmed for 1.9.1-pre3.