4.9: Unable to get to the dashboard

After updating to 4.9, I am unable to get to the dashboard. I can login, and I get the black bar at the top of the window, but it doesn’t function and I have no other way to get into the dashboard.

I cleared the cache but didn’t solve the problem.
I deleted all themes except for twenty sixteen, but then when I try and login, I get an error that tells me that it can’t find the health-care lite child theme, the one that was the active theme.

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