Netlify form submissions returning 400 'Bad request, missing form'

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1

We are using Ajax / fetch, as documented here. Netlify is returning HTTP 400, with body ‘Bad request, missing form’ on every POST. And yet I can find the form submissions in Netlify Forms UI.

Here’s an example submission.

URL: https://www.oceg.org/
Method: POST
Headers:

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36
Content-Type: application/x-www-form-urlencoded

Body:

form-name=Onboarding&redirectUrl=%2Fuser%2F%3Fsuccess%3DYour%2520answers%2520were%2520successfully%2520saved.&formId=75c28225-4cc7-4fe6-9e7a-ed644103295d&Persona=IT+Professional&Job+Title=CTO&Company=OCEG&Country=United+States+of+America&%5BI+got+an+OCEG+membership+to%E2%80%A6%5D=Maintain+existing+credentials%2Fcertifications&%5BI+got+an+OCEG+membership+to%E2%80%A6%5D=Qualify+for+a+promotion&%5BI+prefer+to+learn+by%E2%80%A6%5D=Reading+eBooks+and+standards&%5BWhat+disciplines+are+you+interested+in+learning+more+about%3F+%5D=Decision+management&%5BWhat+topics+are+you+interested+in+learning+more+about%3F+%5D=Data+privacy&%5BTo+achieve+my+career+goals%2C+I+plan+on+spending%E2%80%A6%5D=%3Cb%3E15+minutes%3C%2Fb%3E+a+week+to+learn+%28Committed%29&Other+Comments=&email=slegay%40oceg.org

2

As of 3 hours ago, that form seems to have received a submission. Has something changed here?

3

That’s what I meant by ‘and yet I can find the form submissions in Netlify UI’. The form registers submissions, but Netlify returns error 400.

You can easily reproduce this by submitting a POST request with the details I provided.

4

Where is the form on your website? I tried checking the pages in navigation and could not find it.

5

That specific form is only accessible by authenticated users. You’d need to sign up for free, log in and then go to https://www.oceg.org/user/onboarding/.

But I was able to reproduce this in other forms as well. What I would like to understand is why that POST request with the body and headers I included in my original post is returning error 400. Have you tried reproducing this?

6

Looks like the 400 is coming from your Edge Function(s). You have multiple Edge Functions running on that path and one of them is sending the 400.

7

Interesting! That’s very helpful, thanks. I’ll try and track this down.