Audio files do not play in the Inspector Preview [RESOLVED]

I can no longer preview audio files for some reason in Unity 5.

http://i.imgur.com/Fwtb6TC.png

All that shows up is '00:00', and then it refuses to play. This happens for any format. Worked perfectly fine in 4.x
Is anyone else having this problem?

RESOLVED: This behavior seemed to occur only after importing a bunch of audio files. Restarting Unity fixed the problem.