DEBUG - HTTP 401 response from GET http://127.0.0.1:32400/library/sections

New Plex user, just installed 1.3.3.3148 on OS X 10.10.5. My TV is failing to access the DNLA server. Looking at Plesk's logs I get the following pattern on each attempt

Dec 30, 2016 18:23:09.832 [0x110704000] DEBUG - OnBrowseDirectChildren for '94467912-bd40-4d2f-ad25-7b8423f7b05a' with filter 'dc:title,dc:date,res,res@protocolInfo,res@size,res@duration,res@resolution,res@dlna:ifoFileURI,res@pv:subtitleFileType,res@pv:subtitleFileUri,upnp:albumArtURI,upnp:album,upnp:artist,res@pxn:ResumePoint,res@pxn:ChapterList,item@pxn:ContentSourceType,item@pxn:LiveView,item@pxn:LiveViewUpdateID' and sort '', paged as 0 + 20
Dec 30, 2016 18:23:09.833 [0x110704000] DEBUG - Mapped client to profile Panasonic Viera 3D TV using header User-Agent: Panasonic MIL DLNA CP UPnP/1.0 DLNADOC/1.50
Dec 30, 2016 18:23:09.833 [0x110704000] DEBUG - Mapped object 94467912-bd40-4d2f-ad25-7b8423f7b05a to  part 0 on server 
Dec 30, 2016 18:23:09.833 [0x110704000] DEBUG - Downloading document http://127.0.0.1:32400/library/sections
Dec 30, 2016 18:23:09.834 [0x110704000] DEBUG - HTTP requesting GET http://127.0.0.1:32400/library/sections
Dec 30, 2016 18:23:09.835 [0x110704000] DEBUG - HTTP 401 response from GET http://127.0.0.1:32400/library/sections
Dec 30, 2016 18:23:09.836 [0x110704000] DEBUG - Caching document http://127.0.0.1:32400/library/sections as 1784db6d29c21f09f07d18e4a602c24478780ce8
Dec 30, 2016 18:23:09.836 [0x110704000] ERROR - downloadContainer: expected MediaContainer element, found html
Dec 30, 2016 18:23:09.836 [0x110704000] ERROR - generateForPlexPath - unable to get directory /library/sections

Any ideas as to what the problem is?

James