I did a factory reset on my openWRT recently and re-setup samba shares, which work great when accessing them from Linux and Windows. However, I'm trying to get DLNA working again with my Roku and openWRT doesn't seem to be sharing any files.
I've confirmed my USB hard drive is mounted under /mnt/sda1. I've confirmed the media directory is set to /mnt/sda1, I've confirmed the "network interface to serve" is all checked. I've restarted multiple times. The roku and windows can see the DLNA server, but it DLNA on the router doesn't seem to be indexing the database of content and serving it.
Checking the log shows:
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface br-lan not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth0 not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth0.1 not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth1 not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth0 not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth0.1 not found
[2019/03/26 17:03:43] getifaddr.c:109: error: Network interface eth1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0.1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0.1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth0.1 not found
[2019/03/26 17:03:44] getifaddr.c:109: error: Network interface eth1 not found
Well, it could very well be that the miniDLNA service starts before the share is mounted and ready.
Try running the following form SSH now (after you confirm the share is available) and see if you see the number of files served increase
/etc/init.d/minidlna restart
I presume the error you included were during the booting but disappear after a while? (or how else you access the router if there is no network interface!)
I think @Hegabo was on the right track, minidlna can just be kind of picky, try going to Luci > Services > minidlna > General Settings and uncheck Enable, click Save and Apply, wait about 30 seconds (make sure it says minidlna not running) and check Enable again, click Save and Apply ( it should still say minidlna not running) and then go to Luci > System > Startup > minidlna and then click Start and check if it's seeing your files.
edit - I don't think #service minidlna stop/start does anything in OpenWrt, it should be /etc/init.d/minidlna stop/start/restart as @Hegabo described, so you might try that again first before trying my suggestion.