Sorry to hear that this caused a problem for a classroom (or at all!)
There was a persistent and nasty packaging problem with one of the sound libraries (it kept looking like it was fixed but then broke again). I’m pretty confident it is now fixed in the 3.0.0b9 beta release so your students could try that or alternatively tell PsychoPy to use a different sound lib by changing the application preferences to this:
['pyo', u'sounddevice', u'pygame', ]
or even just
['pyo']
rather than:
[u'sounddevice', u'pygame', ]
The key is to get PsychoPy to ignore the sounddevice library and use one of the other options.
Hope that gets you running.
If you manage to find out more about this one then let us know
best wishes
Jon