These are the info lines from the log. This setup has been working for a couple of years and got broke with the latest update.
[10/14/17 6:49:24 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-21526, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:49:24 PM BST] ERROR FolderBasedContentDirectory UPnP error: java.lang.NullPointerException
[10/14/17 6:50:42 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: 0, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:43 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-22723, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:51 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-22748, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:52 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-42274, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:55 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-22748, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:56 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-42266, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:50:57 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-43703, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:51:07 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-42266, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50
[10/14/17 6:51:09 PM BST] INFO FolderBasedContentDirectory UPnP request - objectId: folder-43701, browseFlag: BrowseDirectChildren, filter: @childCount,dc:creator,upnp:album,upnp:artist,res,res@protection,res@duration,res@size,upnp:albumArtURI,upnp:searchClass, firstResult: 0, maxResults: 50