--Counter zero problem--

[Idanush]

Yesterday I insalled counter strike zero(I downloaded it from the internet) and everything went fine and I played with no problems at all.
But when I wanted to play it today, after I enter the game and presss the "start match" button, the game just xis and shows a strange error messege. ( the messege is attached in a picture)

Why did it suddenly happen(as I said, a day before nothing was wrong), and I could I fix it?
(AT the first time I installed the game. it always showed that messege so I re-insalled it and when it finally worked I thought the error has been fixed but it suddenly appeared again..)

Thank you very much!