Resolving the ‘Attempt To Submit Corrupted Post Data’ Error in WPForms

Are users seeing “Attempt to submit corrupted post data” when submitting your form? This error usually appears when captcha scripts (hCaptcha or Google reCAPTCHA) do not load correctly, which can happen with caching or optimization plugins.

In this guide, we’ll explain the most common causes of this error and walk you through the steps to resolve it.

Common Causes

Here are the most frequent reasons you might encounter this error:

• Caching/Optimization Plugins: Tools like Breeze or Speed Optimizer can minify or delay JavaScript, which may prevent captcha from loading.
• JavaScript Errors: Script errors in the browser can block captcha from executing correctly.
• AMP Pages: Forms added to AMP (Accelerated Mobile Pages) may not run WPForms’ JavaScript.
• Custom Code Conflicts: If you use custom scripts tied to form submission, they may interfere with WPForms’ validation process.

Resolving the Error

If you’re seeing this error, here are the steps we recommend:

1. Make sure the captcha loads
   • Open your form page and check that the captcha widget or badge (reCAPTCHA, hCaptcha, or Turnstile) is visible. If it doesn’t appear, the script may be blocked by caching or optimization settings.
2. Check the browser console while submitting
   • Open the page with your form, then open the Developer Console (press F12 on Windows or Command + Option + J on Mac). With the console open, try submitting the form.
     If the captcha fails to load, you may see errors related to wpforms.js or the captcha script. These usually point to caching or optimization conflicts.
3. Adjust your caching or optimization plugin
   • If you use a plugin like Breeze or Speed Optimizer, temporarily turn off options that modify JavaScript (such as Minify JavaScript, Combine JavaScript files, Defer JavaScript, or Delay JavaScript execution). Clear your site and browser cache, then test the form again.
   • If the error persists, try deactivating the caching plugin completely and re-test your form.
4. Review custom code or snippets
   • If you use custom JavaScript, disable it temporarily and test again. Make sure custom scripts do not override WPForms validation or the form’s submit behavior.
5. Check WPForms logs
   • To confirm if corrupted submissions were recorded, go to WPForms » Tools » Logs in your WordPress dashboard. This can help you see when and where the issue occurred.
6. Still seeing the error
   • If the problem continues after trying these steps, take a screenshot of the console errors and your caching settings, then contact your hosting provider or reach out to WPForms support for additional help.

That’s it! Now you know the common reasons for the “Attempt to submit corrupted post data” error and how to resolve it.

Next, would you like to learn how to properly test your forms before publishing them? Be sure to check out our complete form testing checklist tutorial for more details.