KeyShot Educational is available to students and faculty for learning purposes only. Thus, any BIP file created in KeyShot EDU will not open in any other KeyShot version.
KeyShot CAD Edition is available as a bundle with your CAD application. Thus, you may only import CAD data from that particular CAD application.
To unlock all importers and features in KeyShot you may upgrade to KeyShot Pro. For more information about upgrading to KeyShot Pro, click here.
If the scene is only a few KBs, it is possible the file has been truncated.
This can happen when KeyShot is closed while saving, or there was no more memory available to complete saving the scene.
Some users have had success opening the scene using Recovery Mode, although this is not guaranteed to work.
If you have Backup revision enabled, under Edit->Preferences->General you can check the scene folder for the serialized backups of your scenes.
If none of these options work, loading an older version of your scene or restoring a backup of your system to a time when this file was available are unfortunately the only ways to recover your scene.