New
#1
Verify the game cache.
Its possible theres an update that was interupted or not complete.
This has fixed it for me in the past when a game done this.
If that doesnt work, the .blob file may be corrupt.
https://support.steampowered.com/kb_...4595-WEXN-6831
Generally it is due to an update or a fresh install. I fixed this problem by resetting my pc and downloading updates and relaunching the game.