I went to my site and saw this:
I think I will reinstall and change passwords.
It probably means you have a widget that’s being a cunt. You should disable some widgets and/or plugins and see if the problem goes away. Then narrow it down until you find the culprit. Then figure out why it happened.
Also, call it a hunch, but I think looking near line 206 in wp-includes/default-widgets.php might give you some insight into what may be going on when the script errors out.
I reuploaded the wp-includes folder and it fixed the problem. WHen I logged back in I saw this massage: