Cannot play sound from iMac Late-2013 through HD Native Thunderbolt I/O 8x8x8 System

Hi, all experts,



I have purchased the Pro Tools HD 11 with HD Native Thunderbolt + HD Omni System. It is connected to my iMac Late-2013 in OS10.9.5 with 1TB Serial ATA SSD. I can play sound at Pro Tools but cannot play any sound from Quicktime, iTunes, Final Cut Pro and other softwares. Once I played sound from those mentioned softwares at iMac, a warning notice pops up, saying "Avid CoreAudio Manager quit unexpectedly" and "XXX(the software for playing sound) quite unexpectedly while using the Avid CoreAudio plug-in." Maybe I have made some mistakes at the setup...Can anyone help? Thousands thanks.



Best regards,

Anna