Perform a factory reset on the chromecast unit by pushing and holding the small button on it. It will instruct you to go to chromecast.com/setup. Follow the steps and the rendering on VLC will once again work.
Perform a factory reset on you chromecast unit by pressing and holding the small button on it. It will instruct you to go to chromecast.com/setup. Go through the steps and it will fix your problem.