Resolve Image Not Loading Issue in Visual Builder

Sometimes, when you upload a logo or image (PNG, JPG, JPEG, GIF, WEBP, etc.) inside FunnelKit Automations’ visual builder to design your emails, you may get an image loading error. 

The error message is shown in the image below:

In this document, we'll share the reason behind this issue and how to resolve it. 

Why Are Images Blocked in FunnelKit Automations Visual Builder?

FunnelKit Automations' Visual Email Editor operates from a dedicated domain, app.wpmailkit.com, rather than your WordPress installation. When you insert an image into the email editor, the editor first renders it on app.wpmailkit.com rather than your website.

This process is known as hotlinking, where external assets are loaded from a third-party source rather than your own hosting environment.

Many web hosts implement hotlink protection by default as a security measure, preventing external domains from embedding media files. As a result, these images may fail to render properly, often triggering display or loading errors in your emails.

✅ Quick Fix: Allow FunnelKit's Domain to Access Your Images

To fix this issue, you need to make sure your server treats app.wpmailkit.com as a partner and allows image embedding.

For this, you need to do two things in your hosting server: 

• Whitelist app.wpmailkit.com in your server's hotlinking protection rules
  
• Ensure CORS headers (if required) allow cross-domain requests

However, the process may vary depending on the server you use to host your WordPress site. 

🛠️ Fixes Based on Hosting Environment

In the following sections, we will share how to resolve the issue of the image not loading on different servers.

1. Apache (Most WordPress Hosts)

Edit your .htaccess file (in the WordPress root folder) and add the following: 

RewriteEngine On
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^https://(www\.)?yourdomain\.com [NC]
# Whitelist app.wpmailkit.com:
RewriteCond %{HTTP_REFERER} !^https://([a-z0-9]+\.)?app\.wpmailkit\.com [NC]
RewriteRule \.(png|jpe?g|gif|webp)$ - [NC,F,L]

2. Nginx

Add to server configuration:

location ~* \.(png|jpe?g|gif|webp)$ {
  valid_referers none blocked yourdomain.com *.app.wpmailkit.com;
  if ($invalid_referer) {
    return 403;
  }
}

3. Cloudflare

For Clouflare hosting, you need to do two things: add a new firewall rule and add hotlink protection. 

Here are the details. 

• Firewall Rules:

Create a rule to allow:

(http.request.uri.path contains ".png" or .jpg or .jpeg or .gif or .webp)

and (http.referer contains "app.wpmailkit.com")

• Hotlink Protection:

Add *.app.wpmailkit.com to allowed domains.

4. LiteSpeed

Edit your .htaccess file (in the WordPress root folder) and add the following: 

RewriteEngine On
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^https://(www\.)?yourdomain\.com [NC]
# Whitelist app.wpmailkit.com:
RewriteCond %{HTTP_REFERER} !^https://([a-z0-9]+\.)?app\.wpmailkit\.com [NC]
RewriteRule \.(png|jpe?g|gif|webp)$ - [NC,F,L]

Once you are done making the changes, test if the images are loading correctly. 

🔍 After Setup: Test & Verify

After implementing changes:

1. Clear All Caches:
   
   • WordPress cache (WP Rocket, W3TC, etc.)
   • Server cache (if applicable)
   • Browser cache (Ctrl+F5 or clear browsing data)
     
2. Check in Email Editor:
   
   • Open editor in a fresh browser session
   • Verify that images load properly
   • Check browser console (F12 > Network tab) for errors

3. Should return HTTP 200 (not 403)

Advanced Verification:

curl -I -H "Referer: https://app.wpmailkit.com" https://yourdomain.com/image.png

🧩 Troubleshooting: Still Not Working?

Here are some final checks:

1. If you're using Cloudflare and your images still aren’t showing up—even after setting all the correct rules—check if the "Under Attack Mode" mode is turned on.

This setting can override all your other rules.

If it’s enabled, try turning it off and wait for about a minute. Then, check again.

2. If issues persist even after following the process we shared, you need to: 

• Double-check server configuration
• Try a different browser or incognito mode
• Contact support with:
  • Server type
  • Screenshot of console errors

To contact support, email us at [email protected].