For several days my TV don't play MKV (3D or otherwise) stored on the PC, before it worked: these MKV files were read.
I use Windows Media Player 12 as DLNA server with which I can play MKV files on my PC since I installed the K-Lite Mega Codec Pack.

If I plug a USB device into the TV with the same MKV on, the TV plays them.

Do you have any idea ???

Thank you for your help.