So something new I noticed in the latest Synology firmware: there’s a firewall feature now available. But I found it conflicted with my DLNA/uPnP server. So how did I fix this?
Firstly, I restarted the “Media Server” (it’s at the Package Center, selecting the Media server and then stopping and starting the server).
When I started the server, the very intelligent firewall opened a prompt to let me know that the firewall was blocking the DLNA/uPnP server which needed to allow the service.
Need to check the firewall settings? Go to the Control Panel, and under Connectivity select Security - the firewall settings has a separate tab.