Synfig refuses to render video sequence

OK, seem to have sorted the crashing problem. Now, I have made a simple animation it is 122 frames, it plays OK in Synfig and in the preview player but when I render it out it creates an empty file. What render settings should I be using? I am changing the file extension to .AVI, everything else I am leaving as stock. Any help/advice appreciated.

Hi there!
I usually use filename.avi. I choose target as ffmpeg and parameters as xvid as video codec. It works fine.