My Denon AVR-313 can play flac files up to 24/192 without problems, but the Denon remote app will not recognize any flac files. It will Find the files in the DLNA database, but will not play them as flac.

When I look at the uPnP db I see the following.
Queeze Server has two DIDL-Lite entries
For instance 
http://10.0.0.3:9002/music/261/download.flc
and
http://10.0.0.3:9002/music/261/download.aif

When I use the Synology media server the file plays fine.
The Synology media server has only one DIDL-Lite entry for the exact same file.

http://10.0.0.3:50002/m/NDLNA/4841.flac

Note the difference in extension;
Squeeze Server == flc
Synology media Server == flac

It looks like the Denon Remote app for Android doesn't recognise the extension flc and therefore asks for the aif file.

I think that the LMS D-Lite entry is misspelled and the down Load file extension should be flac, with 'a', instead of flc without 'a'