Preparing to replace php5-common 5.5.0+dfsg-14ubuntu1 (using .../php5-common_5.5.0+dfsg-15ubuntu1_i386.deb) ... Unpacking replacement php5-common ... Setting up apache2 (2.4.4-6ubuntu3) ... ERROR: Module mpm_prefork is enabled - cannot proceed due to conflicts. It needs to be disabled first! dpkg: error processing apache2 (--configure): subprocess installed post-installation script returned error exit status 1