Getting an Error at launcher bootup

[Mesarthim]

I don't have that folder anywhere in my PC and I still can't launch.

Because it's not a local issue. Steam is just overloaded in this case due to the steam summer sales. If you can open the launcher and get the error to try again later, just repeatedly hit the cogwheel and back arrow to refresh the login until it shows up. That's all you can really do in this instance.