Form not working - constant error message

Hey everyone,

I’m having issues with forms on my site, and only managed to find a bunch of topics where people had had the same issue but the problem had been solved w/o a walkthrough of how exactly.

I have a form on my site here:
Published site, site preview.

The form “works” in the sense that it prompts if a required field is empty; the “waiting” text appears when clicking the submit button, etc. However it constantly gives me the error message, and nothing goes through.

To make sure I’ve got only this one form throughout the site; it has a unique name and an ID.

I have some custom code on my site, but have removed all the unnecessary stuff and tested it to no avail.

Any idea what’s the problem? :frowning: