Game unable to start

It's possible something could have cached a bad copy of the client between your computer and the patching servers.

We have deployed a new patch since you reported this (0.9.12i) so if you try to patch again it might just work.

If it still doesn't though you should be able to download a new installer (using the "Download Now!" button up there ^^) and reinstall using that, which will have the latest version of the client in it.