Could you share more details on what's happening along with your system specifications (CPU, GPU, RAM, OS version)? Does it happen to all the media files you try to track? Also, a screenshot of the error would be helpful.
Without more specific info about what's going on in your composition, at which point the error comes up, system info and so on we can't really tell you much. Show us a screenshot and provide the pertinent details. Outside that the usual things apply: Check your hardware acceleration settings, update your graphics driver if necessary, make sure the connections to the external processes and temp files are not being blocked.