I’m one of the people who reads and processes the feature requests that are submitted for After Effects, so I know how many requests we get for the ability to save projects backward so that they can be opened by a previous version of After Effects. It’s a lot of requests.
So, in After Effects CS5.5, we’ve added this feature. You can now save a project from After Effects CS5.5 as a project that can be opened in After Effects CS5 or later. The command is File > Save As > Save A Copy As CS5.
There are caveats, though. Chris and Trish Meyer cover this new feature and its caveats in this video on Adobe TV.
Features that are in After Effects CS5.5 but not in After Effects CS5 are not retained when you open the project in After Effects CS5. However, (most of) the features that are new in After Effects CS5.5 are still stored in the project, so you can still open the After Effects CS5 copy of the project in After Effects CS5.5 and get those features. The video from Chris and Trish Meyer shows a couple of examples of this working.
This doesn’t work in all cases, though, such as in those cases in which a feature has been reorganized rather than merely added in After Effects CS5.5. For example, the 3D Glasses effect has new properties in After Effects CS5.5, and these properties aren’t saved in the After Effects CS5 version of the project. If you find any instances in which the conversion between project versions doesn’t work as expected, let us know with a bug report.
Please keep those feature requests (and bug reports) coming. We really do value them and consider them.
For more about what’s new and changed in After Effects CS5.5, including details on how to order, see this post.