On Mon, Jan 28, 2013 at 6:03 AM, Nick Malleson <[log in to unmask]> wrote:
No, I haven't made any modifications. I have geomason in its own directory
and add the mason jar (and all other libraries) to the CLASSPATH. The
exception is thrown after all the GIS data have been read at the point it
tries to create the visualisation.

Is this the GeoMason checked out from subversion?  Or from a tar ball? If the latter, what version are you using?