Since Luci no longer seemed to work on my Omnia, I did a little digging, and noticed the following errors when starting lighttpd: [typos possible, since I was unable to copy/paste]
Undefined config variable: var.vhosts_dir
2018-10-03 09:43:50: (configfile.c.1289) source: /etc/lighttpd/modules.d/30-simple_vhost.load line: 18 pos: 45 parser failed somehow near here: *
2018-10-03 09:43:50:(configfile.c.1289) source: /etc/lighttpd/lighttpd.conf line: 37 pos: 8 parser failed somehow near here: (EOL)
After uninstalling package lighttpd-mod-simple_vhost this problem went away, and lighttpd started again. I don’t remember if I installed this module in an experiment to serve a website to external users (which failed in the end, so I opted for nginx), or if it’s part of the standard installation.