The file extension AEP is used by the video compositing and animation software Adobe After Effects for project files. In addition to references to videos, audio files and images, AEP files also contain cut and timeline information and effects settings.
Usually, the paths to the media files are also saved, so that they are only found if they are in the original directory. But you can also load AEP files and specify new locations for missing files.
It should be noted that AEP files are usually not backwards compatible, so with the CS4 version, for example, no CS3 compatible AEP files can be created.
Most often resolving problems with opening AEP files is very simple. Just install an appropriate program that supports such files. All of the listed programs support AEP files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of AEP files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate AEP files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe After Effects applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe After Effects has been installed.
Sometimes problems with opening AEP files may not lie with the application itself, but can arise due to other causes, such as: