Error: unpacking 0.209 - natives-windows.jar

When it starts Minecraft it did not want to open, the launcher says that it is opening, but this does not happen, I've waited a lot, tried several times and already rebooted the computer, but nothing works, before the release, says it is: unpacking 0.209 - native-windows.jar, and in theory the game would open, but it does not. My minecraft is vanilla.What is happening?