Multisite 500 Server Error

I am new to Multisite. I recently set up a VPS with cPanel on ASmallOrange servers.

I followed WordPress instructions for enabling Multisite. Edited my wp-config, .htaccess, etc. Worked like a charm. I configured it to use SubDomains, and I set up a wildcard domain through cPanel.

My website’s home page is accessible. My dashboard is accessible. But when I go to the Network Admin > Dashboard, it gives me a 404 error, and if I try to go to the Network Admin > Plugins, Users, Sites, etc, it gives me a 500 error.

I have browsed the forum but found nothing like my issue. Most others were at least able to create a site and have it fail. I can’t access anything in the Network Admin at all.