“There has been a critical error on your website.” how to fix this

I got this message after I updated the jetpack plug in. How do I fix this? I cannot access my admin page.

There has been a critical error on your website. Please check your site admin email inbox for instructions.

Learn more about debugging in WordPress.

• This topic was modified 2 days, 6 hours ago by t-p. Reason: Moved to Fixing WordPress from Everything else WordPress

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