Rekordbox Video - Preview won't play

Mac OS X Yosemite 10.10.5

I am running Rekordbox Video for the first time on my DDJ-RZX, and I am having trouble getting videos to actually show up on either deck from my video playlist. If I drag a video file from my finder directly to the preview, it will load the image, but it won't play the video file. Couldn't even get the practice video files to load/play. I fear that my mac is too outdated, but am trying to make it work. Any help would be greatly appreciated!