You have the old launcher?
If yes, so you need to uninstall all lawless launcher then download it again, you are running the old lawless launcher that why it isn't working.
If that doesn't help contact @Shock.
Still not working, I tried all the solutions.
.Run the launcher as admin(not working)
.Delete everything and move it to another folder and re-try( I also re-installed it still not working)
.Try to click on continue and check whether the launcher is updating or not(It just says "UPDATING" and nothing happens)
.Try to delete the main.dll file and retry to run it.(I did it and the error changed : http://imgur.com/a/V0sYB )