Kodi navigation works but won’t play video with Synology NAS.

I am trying to get Kodi to play video from my Synology DS211+. I can navigate to the video files, but when I try to play, there is a significant delay, and then I always get the message “One or more of the items failed to play. Check the log for more information about this message.”

I am running the latest Synology firmware and the latest version of Kodi Krypton. I have tried uninstalling and reinstalling.

I have tried Kodi from my Sony Bravia TV (Sony KD-55XD8577) latest version of Android). My Galaxy S7 Edge (latest version of Android), my PC (Win 10) and my Samsung Android tablet (Note Pro). My Sony Bravia is the device I really want Kodi to work on.

Each time I have followed the setup procedure for Kodi according to the support and various blogs, including YouTube.

I have also configured my DS211+ according to the Synology support notes, including the NFS setup. I have tried connecting NFS and DLNA, but the same failure occurs. My TV is hardwired Ethernet (1GBPS), and my other devices via WiFi. I have been in contact with Synology, and they think it is a compatibility problem with Kodi video playback. I have checked on Kodi Wiki, and it seems that the files I am trying to play should be well with Kodi’s capability.

It is useful to note that every other application I run on the TV or other devices can play all my video files without any problems at all. That is VLC, Archos, MX Video, DS Video (Synolgy’s own App) and the stock “Video” – all play all types of video file on all of my devices flawlessly.

No matter what I do in setting up Kodi or the DS211+ I can always browse the files video files, but it always fails to play them. The error it comes up is “One or more of the items failed to play. Check the log for more information about this message.”

This happens for every type of file I have on my NAS, avi, mkv, mp4 etc. I have quite a large catalogue, and have tried old and new files. Also, the log is always empty.

I have tried everything I can think of and searched through many pages of guides.

Would someone be able to advise me if there is anything else I can try?

Many thanks for your time in advance.
Kind regards, Ben.