L2gen in SNAP

I have downloaded the ‘SeaDAS-OCSWW’ tools into SNAP and am trying to run l2gen on a L1 OLCI image (using .xml file as ifile). When I press run, I get this error “execution exception: java.io.IOException: l2gen failed to create process.

Does anyone know how to get rid of this error?

So you mean that you have created a new external tool adapter?
If so, you should show what you have done.
Or is this tool available by other means?
Maybe you ask at the guys from OBPG (https://oceancolor.gsfc.nasa.gov/forum/oceancolor/forum_show.pl), as they are the provide of this tool.