airplay works fine with one user and not with another
I have wireless network and use Airplay to listen to music. One of the computers on the network has the strange situation where one user has Airplay functioning normally whereas with the other user it does not work. You can choose the Airplay speakers from within iTunes but there is no sound. This has been the case for some time. It was already like this under Yosemite and upgrading to El Capitan has not done anything to improve the situation. Would anyone have any idea of how to rectify this anomaly?
MacBook Pro, OS X El Capitan (10.11.1), null