I think you can't play the file for right permissions or because is using by the pbx file, for it reason says -stream source-
first of all you need to play the file in windows to know if you are capable of ear it, but for stay sure, try to stop all the services of 3cx before you play the file.
you can go to start - run and write: services.msc
then, stop all the services of 3cx
then, go to the golder where is the wav file and try to open with windows media player. if it souns or not, come to this forum and reply Us.
then, start all the services of 3cx again.