WP_CACHE constant is not present in wp-config.php

From what you’ve shared, it seems the WP_CACHE constant is correctly set in your wp-config.php file, but Divi’s Visual Builder is having trouble. This could happen if there’s a conflict between the cache system and Divi’s editor. Here’s a systematic approach to resolving this:

1. Check for Multiple Caching Plugins:
   • Ensure that only one caching solution is active on your site. If you have other caching plugins (e.g., WP Super Cache, W3 Total Cache, or server-side caching provided by your host), consider disabling them temporarily to isolate the issue.
2. Regenerate Cache Configuration:
   • Deactivate and reactivate WP-Optimize. This will recreate the advanced-cache.php file, which ensures caching is set up correctly.
3. Clear and Disable Cache Temporarily:
   • Go to WP-Optimize settings and clear all cache. Temporarily disable caching to see if this resolves the issue with the Divi Visual Builder. If it does, we can re-enable caching and configure exclusions for Divi later.
4. Check File Permissions:
   • Ensure the wp-content directory and its subdirectories (especially cache) have the correct permissions (e.g., 755 for directories and 644 for files). Incorrect permissions can sometimes interfere with caching.
5. Look for Theme or Plugin Conflicts:
   • Divi and WP-Optimize are generally compatible, but sometimes specific configurations or additional plugins can cause conflicts. Temporarily switch to a default theme (e.g., Twenty Twenty-Three) and disable other plugins to test if the issue persists.
6. Examine the Server Environment:
   • Some hosting providers enforce caching or optimization at the server level, which could conflict with WP-Optimize. Check with your hosting provider for any server-side caching or optimization features that might interfere.
7. Debug Mode for Caching:
   • If you’re still having issues, enable debug mode in wp-config.php by adding:

define('WP_DEBUG', true);
define('WPO_CACHE_FILENAME_DEBUG', true);

This will provide additional information in the HTML source of your pages, which could help identify why the Visual Builder isn’t working as expected.

If none of these steps resolve the issue, could you share more details? For example:

• What PHP version is your site running?
• Do you see any errors in the browser console or your server logs when the Visual Builder is failing?
• Does disabling WP-Optimize entirely allow Divi’s Visual Builder to work?

Feel free to update here if you need further guidance. We’ll be happy to help!

Hello, thank you very much for your detailed reply, I did go through all the steps you suggested, then I got the solution from someone at Divi support, which solved the issue, this is what he suggested

“

Based on my past experience with similar issue and type of Error I see, I will suggest a couple of things here:

1) It could be related to ModSecurity and it will not show up any error in PHP error logs. It might be showing up some errors in the Mod Security Error Logs and your Web Host will have access to those logs. That is the major candidate in this type of issue.

Can you please contact your Web Host and request them to set this variable in the config file of ModSecurity (In the modsec2.user.conf file most probably):

SecResponseBodyLimit 1048576

They can either use this value or any higher possible value for the given setting.

They can also check and increase the LimitRequestBody as well.

Once that is updated and confirmed from their end, then you can check again at your end and see how it goes ??

2) If the issue persists,Check with the Web Host if limits are reached on your server.

They can check if you still have enough resources available on your Server. And also check the Tmp folder to see if that is fine and not full.
?

Let me know how it goes after these changes. ??

I want to post it here , so that anyone else running into similar issues can try this