There have been times when the WAV output module on my system was
not functioning, but resetting it to a different available device
(and back if necessary) cleared the problem. I this was more likely
when I had done something unusual to get it messed up, though. I
have also sometimes encountered problems when the file selected was
not capable of being handled by ABox2, such as when it had a
bit-depth greater than 16, or a sample rate greater than 44,100.
I've used the File module in Media Reader mode many times to supply
a familiar signal to some processing chain in ABox2, so I know it
can work, but I usually use different controls, more like this
(which I just now threw together and took this screen shot while it
was playing):