At 19:24 I tried to open Plex DNLA library again. Plex DLNA log files reports some errors, see below
Aug 14, 2017 19:23:43.718 [8880] DEBUG - GET for
http://192.168.21.246:32469/proxy/36472ff21be1c4fcd421/48x48.pngAug 14, 2017 19:23:43.718 [8880] DEBUG - Mapped client to generic profile: Connection: Keep-Alive; User-Agent: Windows-Media-Player-DMS/12.0.7601.17514; Host: 192.168.21.246:32469
Aug 14, 2017 19:23:43.730 [8880] DEBUG - Proxied GET to
http://127.0.0.1:32400/photo/:/transcode?format=png&height=48&url=http%3A%2F%2F127%2E0%2E0%2E1%3A32400%2F%3A%2Fresources%2Fdlna-icon-260%2Epng&width=48&X-Plex-Token=xxxxxxxxxxxxxxxxxxxx: HTTP/1.1 200
Aug 14, 2017 19:23:43.730 [8880] DEBUG - Responding HTTP/1.1 200
Aug 14, 2017 19:24:46.960 [8940] DEBUG - OnSearchContainer for '0' with filter '*' and sort '', paged as 0 + 1000: (upnp:class derivedfrom "object.item.audioItem.musicTrack")
Aug 14, 2017 19:24:46.960 [8940] DEBUG - Mapped client to generic profile: Accept: */*; Content-Type: text/xml; charset="utf-8"; Host: 192.168.21.246:32469; Soapaction: "urn:schemas-upnp-org:service:ContentDirectory:1#Search"; Accept-Encoding: gzip; User-Agent: Microsoft-Windows-XP/2002, UPnP/1.1, JRiver Internet Reader/2.0 (compatible; Windows-Media-Player/10); Content-Length: 617; Connection: Keep-Alive; Cache-Control: no-cache
Aug 14, 2017 19:24:46.960 [8940] DEBUG - Mapped object 0 to part 0 on server
Aug 14, 2017 19:24:46.960 [8940] WARN - OnSearchContainer - unsupported search criteria (upnp:class derivedfrom "object.item.audioItem.musicTrack")
Aug 14, 2017 19:24:46.961 [8940] DEBUG - OnSearchContainer for '0' with filter '*' and sort '', paged as 0 + 1000: (upnp:class derivedfrom "object.item.audioItem")
Aug 14, 2017 19:24:46.961 [8940] DEBUG - Mapped client to generic profile: Accept: */*; Content-Type: text/xml; charset="utf-8"; Host: 192.168.21.246:32469; Soapaction: "urn:schemas-upnp-org:service:ContentDirectory:1#Search"; Accept-Encoding: gzip; User-Agent: Microsoft-Windows-XP/2002, UPnP/1.1, JRiver Internet Reader/2.0 (compatible; Windows-Media-Player/10); Content-Length: 606; Connection: Keep-Alive; Cache-Control: no-cache
Aug 14, 2017 19:24:46.962 [8940] DEBUG - Mapped object 0 to part 0 on server
Aug 14, 2017 19:24:46.962 [8940] DEBUG - OnSearchContainer returning success with 3 objects
Aug 14, 2017 19:24:46.967 [8940] DEBUG - OnSearchContainer for '0' with filter '*' and sort '', paged as 0 + 1000: (upnp:class derivedfrom "object.item.imageItem.photo")
Aug 14, 2017 19:24:46.967 [8940] DEBUG - Mapped client to generic profile: Accept: */*; Content-Type: text/xml; charset="utf-8"; Host: 192.168.21.246:32469; Soapaction: "urn:schemas-upnp-org:service:ContentDirectory:1#Search"; Accept-Encoding: gzip; User-Agent: Microsoft-Windows-XP/2002, UPnP/1.1, JRiver Internet Reader/2.0 (compatible; Windows-Media-Player/10); Content-Length: 612; Connection: Keep-Alive; Cache-Control: no-cache
Aug 14, 2017 19:24:46.967 [8940] DEBUG - Mapped object 0 to part 0 on server
Aug 14, 2017 19:24:46.967 [8940] WARN - OnSearchContainer - unsupported search criteria (upnp:class derivedfrom "object.item.imageItem.photo")
Aug 14, 2017 19:24:46.968 [8940] DEBUG - OnSearchContainer for '0' with filter '*' and sort '', paged as 0 + 1000: (upnp:class derivedfrom "object.item.imageItem")
Aug 14, 2017 19:24:46.968 [8940] DEBUG - Mapped client to generic profile: Accept: */*; Content-Type: text/xml; charset="utf-8"; Host: 192.168.21.246:32469; Soapaction: "urn:schemas-upnp-org:service:ContentDirectory:1#Search"; Accept-Encoding: gzip; User-Agent: Microsoft-Windows-XP/2002, UPnP/1.1, JRiver Internet Reader/2.0 (compatible; Windows-Media-Player/10); Content-Length: 606; Connection: Keep-Alive; Cache-Control: no-cache
Aug 14, 2017 19:24:46.969 [8940] DEBUG - Mapped object 0 to part 0 on server
Aug 14, 2017 19:24:46.969 [8940] WARN - OnSearchContainer - unsupported search criteria (upnp:class derivedfrom "object.item.imageItem")
Aug 14, 2017 19:24:46.969 [8940] DEBUG - OnSearchContainer for '0' with filter '*' and sort '', paged as 0 + 1000: (upnp:class derivedfrom "object.item.videoItem")
Aug 14, 2017 19:24:46.970 [8940] DEBUG - Mapped client to generic profile: Accept: */*; Content-Type: text/xml; charset="utf-8"; Host: 192.168.21.246:32469; Soapaction: "urn:schemas-upnp-org:service:ContentDirectory:1#Search"; Accept-Encoding: gzip; User-Agent: Microsoft-Windows-XP/2002, UPnP/1.1, JRiver Internet Reader/2.0 (compatible; Windows-Media-Player/10); Content-Length: 606; Connection: Keep-Alive; Cache-Control: no-cache
Aug 14, 2017 19:24:46.970 [8940] DEBUG - Mapped object 0 to part 0 on server
Aug 14, 2017 19:24:46.970 [8940] WARN - OnSearchContainer - unsupported search criteria (upnp:class derivedfrom "object.item.videoItem")