SVG Rendering Error

If your file has elements with the inkscape namespace, that suggests it has originated in Inkscape. Or have you perhaps merged in part of an SVG that came from Inkscape?

What this error suggests is that the file has inkscape attributes without the inkscape namespace being defined.

Try this: go through the file and delete any attributes of the form inkscape:whatever="something". That should solve your problem.

If it doesn't, you may need to post the file somewhere so we can look at it.