This message may have various reasons.
Memory capacity problems or faulty setting for video creation. Check the following:
Make sure the selected drive has sufficient storage capacity and you have the corresponding write-permission or that the drive is not write-protected, such as a CD/DVD drive.
Check the following video settings:
Picture size ....some codecs require the pixel values to be dividable by 4, 8 or 16. See Tips for video rendering.
Parameter ...in the codec settings dialog use default values or presets to ensure valid parameters.
Codec .... the codec may not be ready for use or not be correctly installed. Solution: Install a current codec version and check it with a different application.
The following Windows processes may also result in video creation being aborted:
Enabling screen saver or energy saving options or Login dialog appears. For the solution refer to: Optimizing Windows 7 - Disabling screen saver and login page.
During rendering, do not start any processes that may need administrator rights; e.g. installation of programs or control panel settings.