1 File Failed To Validate And Will Be Reacquired -

In Let the client finish the download.

You wait for a download. Nothing happens. You run the scan again. It says the same thing. You launch the game, and it still crashes. If you’re stuck in this loop, here is exactly what is happening and how to break out of it. What Does This Error Actually Mean? 1 file failed to validate and will be reacquired

Here is the complete article.