Client crashes.

This is starting to get annoying. I don't play that often, but I started back up recently and my client has been crashing, closing itself, and it just recently locked my computer up. This most recent time, it reverted to an older league build saying it needs to apply an update. When I let it try and update, it sits on the download box saying 0.0MB/0.0MB. Before it's mentioned, yes, I've tried doing a clean reinstall and no, it isn't my computer. This has never happened before and I only use the pc for WoW and League. WoW has no issues at all.