What to do when there are JavaScript errors affecting a form

Symptom: A form’s fields don’t render correctly, validation misbehaves, the submit button does nothing, or the browser console shows JavaScript errors when the page loads.

Most likely cause: A third-party plugin interfering with Advanced Forms’ (or ACF’s) scripts. The usual suspects are:

• Optimisation plugins that defer, async, combine, or minify scripts (often breaking the load order or executing scripts before their dependencies).
• Caching plugins serving stale JS bundles after an update.
• Other form plugins that re-implement jQuery global handlers or override acf namespaces.
• Theme JavaScript that throws an error early enough to halt subsequent script execution.

How to track down the conflict

The fastest way to find the responsible plugin is the standard WordPress bisection:

1. Make sure you’re testing in a normal browser session (not a private/incognito tab that might cache differently).
2. Deactivate all plugins except Advanced Forms, ACF, and any plugins essential to the page rendering. Test the form.
3. If the form works: reactivate the other plugins one by one, testing the form between each. The plugin you reactivate immediately before the form breaks is the culprit.
4. If the form still breaks: switch to a default theme (e.g. Twenty Twenty-Four). If it works under the default theme, the issue is in your theme’s JavaScript.

For optimisation-plugin issues specifically, exclude Advanced Forms and ACF scripts from any defer/async/combine/minify rules:

• af-forms-script
• acf-input
• acf-input-* (any ACF field-type-specific scripts)
• jquery-core, jquery-migrate

If you’ve identified the conflict and need help

Open a support ticket with: the plugin you’ve identified, the page URL where the form lives, a screenshot of the browser console showing the error, and any relevant config (e.g. the optimisation rules you’re using if it’s a perf plugin). We’ll help work out a permanent fix or workaround.