Error Garry's Modd

Hello,
I have to make a putting has in the daytime necessities for garry mod, but when I make her I have a message " An error occurred during Garry’s update Mod (file of contents corrupted): C:\Program Files ( x86 ) \Steam\steamapps\GarrysMod\garrysmod\ga rrysmod_000.vpk " and after the download begin again.
How can it be done?
Thank you

Reinstall/verify your game installation.