Thank you for the reply. I've tried updating ISPConfig using the update.php file and the APS Installer still does not work.
Your statements are contradictory. You first state:
I can tell you that the APS installer DOES work correctly with that setup tutorial, as I followed it for an install and APS is working fine.
Then, you state that when you followed the guide, it DIDN'T work and you had to run an update script:
In my learning process for ISPConfig on an initial install, I had a similar issue where APS would fail to retrieve the package list and never update. I went and ran update.php from the ISPConfig install directory, and once it was done APS was working fine.
Can you think of anything else that you may have done that fixed the problem when you were having your learning experience?
I can confirm for a fact that you will not have a working server, if you follow the guide. Unless you consider it a working server, even though you have no dovecot, pop3, or imap.
Here are some more small things that are wrong with the guide:
I am considering doing 2 fresh installs tonight on 2 unused computers and see what happens. I will post the results, if I do.