CC 2015 is a first step towards a completely new under-the-hood architecture for AE. Some things are very improved, but other things...aren't. I'd recommend filing a bug report to help Adobe pin down the problem and then use CC 2014 until the next update for CC 2015 comes out later this year. How to Find and Install Previous Version of Adobe Apps in CC 2015 |
Yes, we've all hard the excuse about how this is some kind of major step forward. What it really is is a defective product that should never have been shipped.
It's disingenuous to say some things just aren't improved – the software is unusable in this state.
We're not Adobe's beta testers, we're customers who spend money and rely on their products for to make a living. And they're screwing us over.
I know that there are a lot of areas of CC 2015 that aren't ready; that's why I suggested using CC 2014. It's useable for me though, because I haven't hit that bug. And a lot of people are using it on that OS too, so it's got to be something a bit more specific to your system. That's why I suggested the bug report.
After you file the report, just pretend that they haven't released CC 2015 yet! You could consider trying it again after the update that comes out later this year. Apparently, it will squash a lot of bugs (with your report, hopefully they'll be able to squash another): What’s new and changed in the upcoming update to After Effects CC 2015