Try this -- make a brand-new project file, then import the problem project into the new one.
Nope. Same error.
Can you open it in an older version of AE?
AE CC 2015.3 is a separate install from CC 2015 and CC 2014; you can have all three installed on your machine at once and they will all work with the same project files.
Well I don't have another version on my work machine because it deleted the older version when installing the 2015.3. I can open in on my home machine that I hadn't upgraded yet so it is definitely an issue with the new version. And I really want to start using some of the new features, so not upgrading seems like a last resort and a failure on Adobe's part so I'm hoping there is another solution. Thanks..
Reinstall the older version. Should take you about 10 minutes.
And while that is true and would solve this particular situation, I wouldn't be able to use the new version and have any access to using Cinema 4D Lite. So i'm hoping Adobe has a solution or creates a fix.
Thank you for your assistance
Installing CC 2015 would enable you to change one or two things and then re-save the project file (under a new name, perhaps) and then use the new version to keep working. That's why I was suggesting it.
Instead of that, try moving the .c4d source on disk so that it appears “missing” when opening the AE project. That should work to get you into the project.
What happens if you import that same, troublesome .c4d project in a new AE project?
If you get the same error, import or create a different/new C4D project. What is Options > Rendering pointing to? Try clicking “Defaults” and re-launch AE.
If still no luck, remove the pref folder (save it somewhere so it can be restored if needed):
Mac: user_name/Library/Preferences/Adobe/After Effects/13.8
Win: C:\Users\user_name\AppData\Roaming\Adobe\After Effects\13.8
And try again.
If you file a bug report and share with them the project file and C4D file, I'm sure the AE team would like to poke at it.