Hi Matthew
I found this thread by doing a quick Google for the error I have :
Final Cut Pro: void CGPathAddArc(CGPath*, const CGAffineTransform*
I have the exact same spec iMac as yourself and just booted up FCPX and get the same errors as you are having in the console, while accessing files on the secondary 2TB Internal HDD
When processing a small 5 minutes video to share FCPX crashes and freezes the whole iMac, which then needs to be switched off and rebooted.
This the full error that appears in the console every second FCPX is running:
08/12/2011 21:37:49.837 Final Cut Pro: void CGPathAddArc(CGPath*, const CGAffineTransform*, CGFloat, CGFloat, CGFloat, CGFloat, CGFloat, bool): invalid value for start or end angle.
Sorry but I don’t have a fix as yet, but thought would let you know you are not the only one with suffering with the error.
Will keep you updated if I find a fix..
Cheers
Jules