Multiplayer 14w10b No items when joining

I updated my vanilla server to the latest snapshot, and when I joined, I had no items. I knew I had some. It looked like I had freshly spawned.

I expect this to be with the new UUID system. Clearly, my UUID or whatever wasn't recorded and my inventory wasn't stored in that, so I had technically never joined.

Do I need to put the UUID for every player on my server in somewhere or something? Please help.