I've been having issues all day as well. Starting yesterday the game kept crashing on me with 90001 error. Today trying to patch I got a unable to complete version check [??? don't remember the numbers] and when I tried to redo it I kept getting a Unable to launch. It wouldn't even attempt to patch anymore. So I went to google the issue, followed what people said and nothing worked.

After all of that I deleted the game entirely and reload it. Every few minutes the download stops and gives me a Unable to download patch files [30413][20496] forcing me to restart. Luckily each time it shows there is less to download each time.

Windows 10 screwed everything up for me. I had no issues with windows 8.1.