Troubleshooting 403 Forbidden Errors

Are you seeing a “403 Forbidden” error when saving your form or performing other actions in WPForms?

This error typically means that your server has blocked a request, either due to a security rule or a misconfiguration. While it can seem intimidating at first, the good news is that there are a few common causes—and clear solutions—you can check.

In this guide, we’ll walk through the most frequent reasons you might encounter a 403 error in WPForms and how to troubleshoot them.

What is a 403 Forbidden Error?

A 403 error means that the server understands your request but is refusing to allow it. When this happens in WPForms, it’s usually related to a form submission or save action that is blocked either by WordPress or the hosting server.

You may see a message like this:

The form cannot be saved due to a 403 error

This can occur when working with AJAX requests, especially when adding or saving fields like Dropdowns.

Common Causes of 403 Errors in WPForms

• Expired or Missing Nonce: WPForms uses nonces (security tokens) to verify that requests come from valid sessions. If this token is missing or expired—often due to page caching—you may get a 403 error.
• Caching and Optimization Plugins: Optimization plugins such as WP Rocket, Autoptimize, or LiteSpeed Cache can interfere with AJAX requests if they cache outdated nonce tokens or delay scripts that are required for proper validation.
• Server-Level Security Rules (ModSecurity): Some hosts use tools like ModSecurity to block suspicious-looking requests. In some cases, legitimate requests (such as those containing the word “select”) can be misidentified as SQL injection attempts, resulting in a 403 error.
• File and Folder Permissions: If your site’s file permissions are incorrectly set, the server may be blocked from executing necessary files like admin-ajax.php, which WPForms relies on for background requests.
• Plugin or Theme Conflicts: Conflicts between WPForms and another plugin or your site’s theme can also cause requests to fail. Security or login plugins are the most common sources of these conflicts.

Troubleshooting Steps

Here are a few steps you can follow to isolate and resolve the 403 error:

1. Clear Your Site Cache
   • Clear both browser cache and your WordPress caching plugin.
   • If your host provides server-side caching, clear that as well or reach out to support.
2. Try in an Incognito Window or Different Browser
   • This helps rule out local caching issues or browser extensions.
3. Temporarily Disable Optimization or Security Plugins
   • Deactivate plugins like Autoptimize, Wordfence, or LiteSpeed Cache one at a time.
   • After each change, test whether the form saves or submits properly.
4. Check File Permissions
   • Folders should typically have 755 permissions, and files should have 644.
   • If you’re not sure, reach out to your hosting provider.
5. Use a Default Theme and Deactivate All Other Plugins
   • Switch to a default theme like Twenty Twenty-Four.
   • Deactivate all plugins except WPForms, then try again.
   • If the error disappears, reactivate plugins one by one to find the conflict.
6. Check With Your Host About ModSecurity
   • If the issue persists, contact your hosting provider and ask if ModSecurity or other firewalls are blocking requests to admin-ajax.php.
   • Provide the error message and explain that you’re seeing a 403 error when saving a WPForms form with a Dropdown field.
7. Check .htaccess Rules
   • Look for overly strict security rules. A standard WordPress .htaccess file should look like this:

# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPress

Still Need Help?

If you’ve followed the steps above and still see the error, feel free to reach out to our Trusted Advisors in the support team. Let us know:

• The exact error message you’re seeing
• When the error appears (e.g., when saving a form or submitting it)
• Any steps you’ve already tried from this guide

That’s it! Now you know how to troubleshoot 403 Forbidden error in WPForms.

Next, would you like to explore more troubleshooting tips? Check out these additional tutorials:

• How to Troubleshoot JavaScript Issues in WPForms
• How to Troubleshoot Common WPForms Issues