I have been having this issue for a while. I run an emby server alongside my kodi install on Ubuntu 16.04. I first had the emby add-on so that kodi talks to emby but I started having issues where kodi would freeze while a movie was playing requiring the system to be restarted. To try and fix the issue I tried to disable the emby add-on and install a new nvidia driver for the video card. Unfortunately, neither of these have solved the issue. I have noticed that playing the movies through VLC never causes any issues which disheartens me. Any ideas on how I can figure out what is causing the freezes? Thanks.