A few weeks ago I had the same thing happen only a grey screen was displayed. Did the initial drill: refreshing, closing Hype, etc. several times with no change in the Reflect display - still was grey.
I did a cold reboot and everything was fine. No issues since (no reproducible problems to send a report).
Wrote it off as a fluke.
iMac; OS 10.9.5 - browser probably was Safari.