: This occurs when a piece of data is downloaded but doesn't match the original file's "fingerprint" (hash). Your client will automatically discard the bad data and re-download it, which is normal and usually doesn't mean the final game will be broken.

It refers to downloading a torrent for the game Counter-Strike: Global Offensive . If you are encountering a "fail" or error during this process, it often relates to the following technical features of torrenting: Common Torrent Features & Error Causes

: Torrents rely on "seeders" (people with the full file) and "peers" (people currently downloading). If there are zero seeders, your download will fail to reach 100%.