have you tried getting the render time down in AE to see if that helps? perhaps pre-rendering the c4d component?
Thanks for the reply, I've definitely worked on very similar comps of similar render time in Yosemite and had no problems, it's feeling like a Sierra/Adobe issue.
I've babysat some renders to see what happens and it may be that closing the comp viewer window [ I habitually ~ onto the render queue window before hitting render ] is causing the issue.
Leaving the comp window open to help watch the progress meant AE didn't hang, so I'll run a few more both ways and if that does seem to be the problem I'll log a fault.
Sorry for this issue. Did you ever find a solution? Please let us know if you have or if you still need help.
Thanks for the reply Kevin.
I've had far fewer issues with keeping the comp viewer window open during render but I think 1/10 has hanged at around 98% complete. I don't think its due to complexity in my comp as things get easier processing-wise towards the end of my timeline.
It does seem to be unique to this particular project that the OS upgrade has found something objectionable about.