I solved my problem. Installed plug-in version 3.0.8500. I turn off the plugin with Emby, and then shutdown Freenas server. After that I start Freenas server and when it's start, I enable the plugin with Emby. After few minutes all my devices can see Emby as a dlna server. What was the real problem, I can`t say. But simply turn off and turn on the plugin does not helps.