Dominik B

I've had the same problem and my launcher log had the same issues. I think there's a problem with updating the game or something like that. Here is a solution that worked for me:

I uninstalled the Minecraft Launcher and completely deleted the .minecraft folder in my userfiles. You will find your .minecraft folder using the Win-Search and then search after "%appdata%" and
go to Users[YourName]\AppData\Roaming\.minecraft - MAKE A BACKUP of your savegames! Then i reinstalled Minecraft using a other harddrive-path to install. I'm not sure if this is necessary, but
if you have the option, try it. Then i launched Minecraft and pressed play and all of a sudden the launcher started to download about 400 Mb files and finally worked again. After the game the game has started once,
you may put your savegames back in the .minecraft folder.

I've had the same problem, my launcher log had the same issues. I think there's a problem with updating the game or something like that. Here is a solution that worked for me:

I uninstalled the Minecraft Launcher and completely deleted the .minecraft folder in my userfiles. You will find your .minecraft folder using the Win-Search and then search after "%appdata%" and
go to Users[YourName]\AppData\Roaming\.minecraft - MAKE A BACKUP of your savegames! Then i reinstalled Minecraft using a other harddrive-path to install. I'm not sure if this is necessary, but
if you have the option, try it. Then i launched Minecraft and pressed play and all of a sudden the launcher started to download about 400 Mb files and finally worked again. After the game the game has started once,
you may put your savegames back in the .minecraft folder.

I hate that its happening to me too after the 1.6.1 updating very frustrating