Hello.

My issue since the 1.2.13 update to the Windows 10 version of the game: Sometimes when trying to start up an existing game (or even in creating a new world), a "window/screen ?" pops up quickly that says "Updating 1 of 1 Packs" before going back to the world-choosing screen (see the 2 screen shots for clarification of the 2 screens I'm talking about). The game does NOT go on to the "loading resource packs" and then "generating world" screens (and subsequently starting the game) like it's supposed to. Any further clicking on the worlds to try starting a game produces no further responses from Minecraft. I can X - back to the start screen though. To get into a game I have to shut down Minecraft and start it up again.

Other Notes:

• I am not using any custom texture or resource packs.
• This usually happens after saving and exiting out of a world and then immediately trying to start it (or another world) up again, without closing down Minecraft first.
• I am Not using the Experimental Gameplay feature in my worlds.

How to reproduce:

• Start up a game. Save and exit, leaving Minecraft open. Reload/start the world to play again. (For me, the inability of the game to load happens at this point)