Apache failed | httpd: Syntax error on line 28 of /etc/apache2/conf/httpd.conf: Syntax error on line 2 of /etc/apache2/conf.modules.d/280_mo...d_from_conn

Issue

Issue with Apache:

# systemctl status httpd.service
● httpd.service - Apache web server managed by cPanel EasyApache
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Qua 2023-11-29 02:46:59 UTC; 2min 38s ago
  Process: 5025 ExecStart=/usr/local/cpanel/scripts/restartsrv_httpd --no-verbose (code=exited, status=1/FAILURE)

Nov 29 02:46:59 XXX systemd[1]: Starting Apache web server managed by cPanel EasyApache...
Nov 29 02:46:59 XXX restartsrv_httpd[5025]: httpd: Syntax error on line 28 of /etc/apache2/conf/httpd.conf: Syntax error on line 2 of /etc/apache2/conf.modules.d/280_mo...d_from_conn
Nov 29 02:46:59 XXX systemd[1]: httpd.service: control process exited, code=exited status=1
Nov 29 02:46:59 XXX systemd[1]: Failed to start Apache web server managed by cPanel EasyApache.
Nov 29 02:46:59 XXX systemd[1]: Unit httpd.service entered failed state.
Nov 29 02:46:59 XXX systemd[1]: httpd.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

Environment

• Cloudlinux OS
• cPanel
• ImunifyAV

Solution

Review the error log entry:

httpd: Syntax error on line 28 of /etc/apache2/conf/httpd.conf: Syntax error on line 2 of /etc/apache2/conf.modules.d/280_mod_proxy.conf: Cannot load modules/mod_proxy.so into server: /etc/apache2/modules/mod_proxy.so: undefined symbol: ap_get_pollfd_from_conn

In that output It was about this file having incorrect content: /etc/apache2/conf.modules.d/280_mod_proxy.conf.

Reinstall the package to which the file belongs:

# rpm -qf /etc/apache2/conf.modules.d/280_mod_proxy.conf
ea-apache24-mod_proxy-2.4.58-1.el7.cloudlinux.x86_64

yum reinstall ea-apache24-mod_proxy

and check if httpd service starts:

# systemctl restart httpd.service
# systemctl status httpd.service

If the previous steps didn't help, then:

Renamed the following file:

mv /usr/lib64/apache2/modules/mod_proxy.so /usr/lib64/apache2/modules/mod_proxy.so.bak

And then reinstalled the package again:

yum reinstall ea-apache24-mod_proxy