The OP Lists this exception: "PHP Fatal error: Call to a member function connected() on a non-object in /usr/local/freepbx/amp_conf/htdocs/admin/libraries/utility.functions.php on line 1304"
I seen this exact exception running the install from the install package downloaded here: mirror.freepbx.org/modules/packages/freepbx/freepbx-13.0-latest.tgz, yesterday (Jan 9/16)
To get the exact install log, I would have to create another clean install, but if it helps you to debug it, I can. From memory, just after the installer populates the database tables, it attempts to store a few of the environment vars and throws the exception stated above. Reverting the changes I referenced above, allows it to install cleanly.