Ninja Forms stopped working after theme update

I’ve been using the blossom coach theme for a year and a half, and it’s worked perfectly until now. After the last theme update, all of my forms created by the ninjaforms plugin will not send. They hang after the submission button is pressed and get stuck on “processing”. However the forms do work when I’m logged into the backend of wordpress as an administrator. The forms just don’t work for anyone else that’s not an administrator.

I manage several websites with different hosting companies which use the same plugins and the forms all work because those sites have different themes. It only stops working when the site is set to the blossom coach theme. I’d appreciate any help.

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