Hi Todd,
You say
"We've verified that the Mac OS X v10.9 operating system broke Motion Sketch for After Effects CS6. It's working fine in After Effects CC (12.1)."
So the operating system is not the reason as obviously in the later version (CC 12.1) there is no problem.
Can you please let us know what is the warranty time for Adobe software? We purchased our copy on Sep 2012 in the UK.
Cheers,
Anja