So I just downloaded the 50 MB patch. It applied and I clicked "play". It said the server was offline. That's fine. However, when I re-opened the client a bit later, it said "repair" instead of "play". It gave no indication of there being a problem. I thought the client may have messed up, so I closed it off and restarted it. But now it's making me download 22 GB all over again.

This is unsatisfactory. I had the game installed. I was playing it just fine. The entire game is downloaded and patched. Why is it making me re-download everything?