cannot play mkv - D550 lcd

I can't play mkv (most of my files are mkv with h264 avc).
When I look at the file's properties it shows me he have a 0.0B file size.
I can play the other files (such as mp4 ..).

I look the log , but doesn't understand ...
here's an extract of the log file

  Code:

2013-12-22 14:22:25,712 ERROR [ResourceTransportRequestHandler] Error while processing resource, sending back 500 error. Message: FFmpeg execution failed
java.io.IOException: FFmpeg execution failed
   at org.serviio.delivery.resource.transcode.FileBasedTranscodingDeliveryStrategy.createInputStream(FileBasedTranscodingDeliveryStrategy.java:49)
   at org.serviio.delivery.resource.transcode.AbstractTranscodingDeliveryEngine.retrieveTranscodedResource(AbstractTranscodingDeliveryEngine.java:134)
   at org.serviio.delivery.resource.AbstractDeliveryEngine.deliver(AbstractDeliveryEngine.java:110)
   at org.serviio.delivery.MediaResourceRetrievalStrategy.retrieveResource(MediaResourceRetrievalStrategy.java:153)
   at org.serviio.delivery.GETMethodProcessor.retrieveResource(GETMethodProcessor.java:121)
   at org.serviio.delivery.GETMethodProcessor.buildDeliveryContainer(GETMethodProcessor.java:48)
   at org.serviio.delivery.AbstractMethodProcessor.handleRequest(AbstractMethodProcessor.java:100)
   at org.serviio.delivery.ResourceDeliveryProcessor.deliverContent(ResourceDeliveryProcessor.java:81)
   at org.serviio.upnp.webserver.ResourceTransportRequestHandler.handleRequest(ResourceTransportRequestHandler.java:86)
   at org.serviio.upnp.webserver.AbstractRequestHandler.handle(AbstractRequestHandler.java:61)
   at org.apache.http.protocol.HttpService.doService(HttpService.java:293)
   at org.serviio.upnp.webserver.ServiioHttpService.doService(ServiioHttpService.java:77)
   at org.apache.http.protocol.HttpService.handleRequest(HttpService.java:212)
   at org.serviio.upnp.webserver.WebServer$WorkerThread.run(WebServer.java:192)