Cant figure out why there is a critical error on website

I’ve tried unplugging all plug ins, changed themes and deactivating plug ins and themes that aren’t needed/being used but whenever I try going into my cart or checkout it still shows the Critical Error message. I haven’t been able to figure out what is causing it. I never got a notification or email about this error, when I was in editor it was showing up fine, but when I’m in as a visitor/live mode is when it comes up so I didn’t know about this for a few weeks.

The page I need help with: [log in to see the link]