Hi Khedr,
Although it's hard to tell exactly what's causing your error without a copy of your file to test or OS info, here are a couple of steps to try and export an animation of your results using a Windows OS:
1) Change the video filename destination to a directory other than the default of "C:\Program Files\CHC\BlueKenue64\New.avi" (e.g., assuming a windows operating system, shared computers sometimes do not have write access to C:\Program Files\)
2) Try the different Encoding options (e.g., using Windows 7 OS, "MS Video1" works well for me)
I'm not well versed in the encoding differences, but if you're using a windows OS, I hope these items will help you.
Best regards,
Chris