Fix: Apache Syntax Error — Cannot Load mod_proxy.so in cPanel

Introduction

If you’re managing a cPanel server and suddenly Apache won’t start with this error:

httpd: Syntax error on line 28 of /etc/apache2/conf/httpd.conf: Syntax error on line 2 of /etc/apache2/conf.modules.d/000_mod_mpm_prefork.conf: Cannot load modules/mod_mpm_prefork.so into server: /etc/apache2/modules/mod_mpm_prefork.so: undefined symbol: ap_set_listentcpdeferaccept

This is a common Apache problem when the mod_proxy module cannot be loaded, usually because the module is missing or corrupted. In this blog, we’ll help you with an easy fix Apache Syntax Error — Cannot Load mod_proxy.so in cPanel

Prerequisites

Before starting, make sure you:

Have SSH access to the server
Logged in as root or a user with sudo privileges
OS: CentOS/AlmaLinux/RockyLinux/CloudLinux server with cPanel installed

Why This Error Happens

The error ” Cannot Load mod_proxy.so” appears when Apache tries to load the mod_proxy module from:

/etc/apache2/conf.modules.d/280_mod_proxy.conf

 but the module file (mod_proxy.so) is either missing, corrupted, or improperly referenced. In rare cases, core Apache modules may not have installed correctly or got damaged after an update.

Step-by-Step to Fix

Follow these commands in order to resolve the issue:

1. Update System Cache

dnf makecache

This ensures your package manager has an updated list of packages.

2. Reinstall Apache with cPanel’s EA4 Package

dnf reinstall ea-apache24

This reinstalls Apache and its core modules (including mod_proxy), fixing broken or missing files.

3. Verify mod_proxy Is Enabled

Open the file:

cat /etc/apache2/conf.modules.d/280_mod_proxy.conf

You should see:

# Enable mod_proxy
LoadModule proxy_module modules/mod_proxy.so

If the LoadModule line is commented out (# at the beginning), remove the # to enable it.

4. Rebuild Apache Configuration

After reinstalling and enabling the module, regenerate the Apache config:

/scripts/rebuildhttpdconf

This builds a fresh and valid Apache configuration based on your system’s modules and settings.

5. Restart Apache

Finally, restart Apache:

/scripts/restartsrv_httpd

If everything is correct, Apache should start normally.

Conclusion

This Apache error — “Cannot load mod_proxy.so into server” — happens when core modules become unavailable or corrupted. By following these steps, you restore a clean Apache setup and get your server back online fast. If you’re encountering the Cannot Load mod_proxy.so Apache error in your cPanel environment, it’s a clear sign that your server configuration needs expert attention. Issues like these can impact website availability, performance, and overall server stability if not handled correctly.

Instead of spending hours troubleshooting complex Apache and cPanel configurations, let experienced professionals like us take care of it for you. With our reliable cPanel Server Management Services, experts can quickly diagnose the root cause, fix module loading errors, optimize Apache settings, and ensure your server runs smoothly without recurring issues.