I've been having issues with this games launcher ever since September 21st with the second EoD beta event. It's an issue that seems to have affected only small percentage of players when it initially happened, and in my case I was always able to get my launcher to work with some of the common solutions that I've been seeing in the forums. Every few patches between then and now seemed like it would get a little worse, but even then I could still get my game to eventually work.
This is the latest patch where I've had the launcher won't even open, and I feel like I've tried everything. I don't like using the phrase "literally unplayable", but as of right now for me, and a now larger percentage of people, I feel like it's appropriate.