Asustor 608t will suddenly no longer connect to Emby

[Stonekeep 0]

So have been running an Asustor 608t with all my videos on with absolutely no problems when suddenly the server can no longer be found in Emby  server. I’m a complete novice so I’m probably to blame but I don’t understand how it has just erased the server connection . Any help would be gratefully received. 

[Luke 42077]

Hi, what exactly do you mean by "server can no longer be found in emby server" ? 

What exactly is not found and from where? can you please show a screenshot example? Thanks !