I installed Metro 6.2.3 and did some editing and mixing down. Everything worked fine. Then I loaded an instrument into ST2 or GPO or tried NI's B4 and instead of being able to record I get this alert message.
"The core audio driver returned either an invalid or null audio stream."
The stop button then starts to flicker a bit. Metro 6.2.3 crashed once also. When I use the previous version it records fine. I have energy saver at "Highest".
Before I upgraded to Metro 6.2.3 I installed Apple's latest security update that came out today and then repaired permissions.
iMac G5 1.8ghz.