James Cook wrote
I've just set up a new partition on my server to use for my web server. It's running OS X El Capitan.
Everything has been installed just fine, but I can't get the ports activated. I'm sure that nothing else is using the ports - the system was installed fresh just a few hours ago, so there's nothing left over.
Restarts haven't resolved it either.
What else can I try to get those ports activated?
What is the type of the partition that you have created? Only native MacOS partitions (HPFS/APFS) support making an executable flagged as SETUID. FAT, NTFS and other types of partitions do not support that flag.
This flag is important to make the OS start the executable as root and get access to ports < 1024.
Alternatively, you can set Abyss Web Server as a startup item. Usually, this makes the application start during boot time as a super privileged user an then it can have access to ports < 1024.
We'll be waiting for your feedback.