world loader bug

Is this still an issue in the current Minecraft Snapshot 15w45b or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Please attach the complete output of the "Game Output (Your Minecraft name) " which can be found on the fourth tab of the launcher to this ticket.

If the launcher closes after game start, please edit your profile and select "Launcher visibility" then, "Keep the launcher open".

Ticket resolved as incomplete, because no answer in a reasonable amount of time (1+ year), if it still happens, please update the ticket.