I'm installing PHP 5.4 with Apache 2.4 on Ubuntu 14.04. Php 5.4 is not available on apt-get so I have to install it from source. I have installed


And i configured PHP with

./configure --with-apxs2=/usr/bin/apxs2 --with-mysql --with-curl

Then i build and install. I added this lines to /etc/apache2/apache2.conf:

LoadModule mpm_event_module /usr/lib/apache2/modules/mod_mpm_prefork.so
LoadModule php5_module  modules/libphp5.so
AddType application/x-http-php  .php

When I try to restart Apache I get this error:

module mpm_event_module is already loaded, skipping

I searched inside the .conf file, but the module was not loaded there before. EDIT:

As by @Andrew Schulman answer I could find it in


When I run

a2enmod mpm_event

I get this:

Considering conflict mpm_worker for mpm_event:
Considering conflict mpm_prefork for mpm_event:
Considering conflict mpm_itk for mpm_event:

How do I solve the conflict?


I used




and loaded the mpm_prefork_module. Apache restarts ok, but when I try to run

a2enmod mpm_prefork_module 

I get this:

ERROR: Module mpm_prefork_module does not exist! 

What does it mean?

  • You need to disable mpm_event, then enable mpm_prefork. – Andrew Schulman Apr 13 '15 at 9:10
  • Look again at the commands I wrote in my answer. You want mpm_prefork, not mpm_prefork_module. – Andrew Schulman Apr 13 '15 at 12:21
  • Hint: If you type a2enmod mpm_pre and press TAB, the shell will take care of the rest for you. – Andrew Schulman Apr 13 '15 at 12:23

You can find it by grepping through the whole Apache configuration:

grep -r mpm_event_module /etc/apache2

It's almost certainly in /etc/apache2/mods-available/mpm_event.load. In Debian/Ubuntu the standard way of enabling and disabling Apache modules is to run e.g.

a2dismod mpm_event
a2enmod mpm_prefork

See man a2enmod, and similarly man a2enconf and man a2ensite.

  • Thanks @Andrew Schulman. Your solution is working. I used a2dismod mpm_event a2enmod mpm_prefork. Thanks. – Foysal Mar 27 '20 at 13:44

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