YT in html form

Youtube went suddenly into a simplistic html form in chrome.
Win10 updated itself a few days before that, worked fine, and without any warnings, actions or other triggers that I can recall went into this odd mode.

Tried searching google but I can't find the words to describe it as I'm no IT guy.
Just a white page with blue text links, looks like a 1993 basic webpage...
Anyone got a quick fix or should I just reinstall chrome?