Steam re-downloading game?

[Brumboy]

Ok so I'm downloading Batman Arkham Knight..and for the 3rd time now it's redownloading the ENTIRE game!

This evening it had almost finished downloading the 33GB game..left it on all night and for some reason it restarted the download from scratch.

I have left it downloading AGAIN and after 5GB it did the same thing!!!

This is frustrating, why on earth is it doing this?

Someone help

 

[Brumboy]

Oh I see, as long as it's a common problem that's fine.

Any links to information on this mate?