Fixing ajaxSubmit and eForm 500 Errors in Evolution CMS

When eForm works in normal mode but breaks under ajaxSubmit, the problem is usually not the form fields themselves. The failure tends to appear in the parsing and response-handling layer, especially when the returned HTML is not what the AJAX helper expects.

Typical symptom

The request returns a 500 error, and the stack trace points into DOM or parser-related code instead of the form markup. That usually means the AJAX layer tried to parse or transform a malformed or unexpected response.

Typical setup

[[ajaxSubmit? 
  &noJQuery=`1`
  &container=`.b-callBack`
]]

<section class="b-callBack">
[!eForm?
  &formid=`callBackForm`
  &tpl=`callBackForm`
  &to=`mail@mail.net`
  &from=`mail@mail.net`
  &thankyou=`callBackThankyou`
  &report=`callBackReport`
!]
</section>

What to check

• Whether the returned HTML fragment is valid and complete.
• Whether the thank-you and report templates render something the AJAX parser can handle.
• Whether a custom build changed parser behavior around document-source parsing.
• Whether the AJAX container selector matches the actual frontend markup.

In older Evo setups, the fix is often to simplify the response contract first, then reintroduce richer HTML once the AJAX flow is stable.