Black screen when starting to play recorded video is often caused by using the "Also BVR" checkbox and Intel hardware acceleration.  This is in 
Blue Iris camera settings > Video tab.  However back in January H.265 hardware acceleration with Intel wasn't even working so I am not confident that this is really the problem.
If you are recording to MP4 that could be a problem too.  BI sometimes has issues with MP4 playback.