Minecraft marche pas

bonjour j ai un problème avec minecraft
Pendant son chargement sa me met sa :
FATAL ERROR: net.minecraft.bootstrap.FatalBootstrapError: Unable to un-pack200: java.io.FileNotFoundException: /Users/Alfredina/Library/Application Support/minecraft/launcher.jar (No such file or directory)
at net.minecraft.bootstrap.Bootstrap.unpack(Bootstrap.java:159)
at net.minecraft.bootstrap.Bootstrap.execute(Bootstrap.java:123)
at net.minecraft.bootstrap.Bootstrap.main(Bootstrap.java:381)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at apple.launcher.LaunchRunner.run(LaunchRunner.java:116)
at apple.launcher.LaunchRunner.callMain(LaunchRunner.java:51)
at apple.launcher.JavaApplicationLauncher.launch(JavaApplicationLauncher.java:52)

Please fix the error and restart.

Aider moi svp