Pro Tools 10.3.8 hangs at "Setting up I/O paths... Analog 1-2"

Just installed a new Mac Pro 6,1 6 core, and no major issues, but when loading the splash screen/plugs/etc, it hangs on the last step, setting up the I/O paths. I can run sessions, but waiting 5 minutes at that point every time I start Pro Tools is beyond annoying- I'm sure you can all relate. Was never an issue before the new Mac and Mavericks. I've done all the things usually expected to solve an issue like this- trashing prefs etc, setting default I/Os .. but nothing is fixing it. Has anyone else encountered this issue?



Thanks!