Character Movement suddenly doesn't work?

I’ve been building my Player over the default Third Person controller and during some intense Graph-building, the Character component suddenly stopped working without my ingeration. Its details are gone and trying to reference it gives errors (“none reference”.) If I make a new Character actor, its new character movement works normally. What the hell could happen and how can I fix it or bring it back to default state?
See screenshot: https://i.imgur.com/bDZUmdJ.png