Freeform Pro: intermittent error "Invalid form id(s) submitted"

Question

I have a Freeform Pro standard (non-composer) form. I cannot reproduce the issue, but I have gotten a report of this error: "Invalid form id(s) submitted".

Secure forms is already turned off for this site, so we can rule out XID issues. My form tag looks like this:

{exp:freeform:form
  form_id="3"
  required="lastname|firstname|address|city|state|zip|phone_number"
  form:class="freeform"
  inline_errors="yes"
  return="{current_url}"
}

Yes, there is a form with an ID of 3 in the system. I have been able to submit the form myself with no issue.

Most of my research on this error reveals that it's either an XID or htaccess issue. But I don't think either of those apply in my case, since the form works most of the time, and since secure forms are turned off. What other reasons would this error occur?

EE 2.5.5 Freeform Pro 4.0.12

There is no budget for upgrading EE.

EDIT: There's also no caching on this form, no tag caching, no CE Caching, no Stash caching.

Answer 1

I had a similar error, and it was distinctly user-error. But here are two items which might help.

Do you have any sort of caching turned on? It could potentially be that. If so, try disabling the caching for that particular page.

Also, try this: Fill out the test form, hit submit. Hit the 'back' button, and submit the form again. I know Freeform will spit out an error when you do that. I don't remember exactly what that error message is, but it's related.

But this is also cache related - if you submitted a form, when you hit 'back' to go back a step, you're going to a locally cached page, which would have an ID of the one you already submitted.

Answer 2

Hmm, I had a similar issue. I was using AJAX to submit a Freeform form and then wanted to offer the user the ability to re-submit again after for a colleague without reloading the page but I was getting the below on the 2nd submit:

{"success":false,"errors":["Invalid form id(s) submitted."]}

It transpired that my JS which was clearing the form inputs after the first submit was also clearing the hidden inputs generated by Freeform (params_id and CSRF), hence the error. Might not help but hey...