Synology NAS recognitin

I recall getting a ‘no servers found’ when there are server issues, rather than ‘source err’. I’m assuming that both the SU and Synology are on your network and that you are not trying to plug the nas into the SU directly?

The upnp server lives in the nas, so it’s not a case of your upnp server not recognising the Synology. Once you’ve checked it’s connected properly, enable the Synology media server than comes prepackaged with the nas. Once that is working you can get Minim set up properly. Minim has benefits of you want to transcode flac to WAV and play gapless. If you don’t, the Synology server may be all you need. 

Also I have found the minimserver actually sounds slightly better than synology media server too, so well worth trying to sort it out. 

It looks like you've done everything I would do - rebooted Uniti, NAS & router & re-indexed.    I agree HungryHalibut suggestions to install Synology's 'Media Server' just incase Minimserver is having problems.   

Getting back to the rebooting,  I'm tempted to do all that again,  but please make sure its done in the right order.  Leave the router off for 5 minutes to be sure the ISP knows its gone offline,  then restart router & let it finish,  then the NAS,  then the Uniti.

Thanks for the responses, I have searched through Synology setting and found a device List for Media Streaming.  Naim recently upgraded my board whihc is visible but not ticked off. Hopefully this will resolve the issue.