Comment 2 for bug 1707375

Thanks for filing this bug in Ubuntu.

This is possibly the error:
Setting up apache2 (2.4.7-1ubuntu4.16) ...
ERROR: Module mpm_event is enabled - cannot proceed due to conflicts. It needs to be disabled first!
dpkg: error processing package apache2 (--configure):
 subprocess installed post-installation script returned error exit status 1

That error message is printed when a2enmod is called to enable another mpm module without disabling the current one first.

For example:
ubuntu@trusty-apache:~$ sudo a2query -M
event
ubuntu@trusty-apache:~$ sudo a2enmod mpm_prefork
Considering conflict mpm_event for mpm_prefork:
ERROR: Module mpm_event is enabled - cannot proceed due to conflicts. It needs to be disabled first!
Considering conflict mpm_worker for mpm_prefork:

Somehow you got yourself into that situation during package installation.

Could you please provide the following:
- output of "sudo a2query -M"
- output of "sudo /usr/sbin/apachectl -D DUMP_MODULES" (might fail, as it did fail when apport opened this bug)
- ls -la /etc/apache2/mods-enabled/
- dpkg -l|grep apache

Thanks