Wd tv live wont play wd 1tb portable hard drive

Hi, just got a wd tv live media player today so I could play my portable hard drive on tv. When I plug it into wd tv box lights on both units just flash. Please help. Hard drive is near full

If you have a lot of files it will take some time to scan and get content if you have Media Library turned on.  Also if you are powering the drive by USB than the WD might be supplying insufficient power add external power for HD.