As I'm sure you've worked out, docx4j is using image magick to convert the SVG to a PNG.
(Word 2007 can't open an SVG).
I just tried adding an SVG myself.
- I installed ImageMagick 6.6.4 (on Windows) and renamed the executable to imconvert
- I restarted eclipse (this seemed to be necessary in order for it to read the updated system path, and avoid "CreateProcess error=2, The system cannot find the file specified")
After that, it worked for me.
Googling for "convert.c ConvertImageCommand" might help with your specific issue? Let us know how you go, thanks.
cheers .. Jason
ps i've created a separate thread for your other question.