Getting blank screen unless admin

Hi,

I’m running Garfunkel Child for my site — http://www.studiotoschool.com — and can only see the site when logged in as an admin. All other users (and members of the public) just see a black screen when they try to visit the site.

I tried deactivating and activating plugins one by one, and this didn’t resolve the issue. I temporarily updated the theme to Twenty Seventeen and that resolved the problem. However, I want to go back to the Garfunkel theme, and have users be able to see and access the site. Help!