Mod_python error: "PythonHandler mod_python.publisher"

Traceback (most recent call last):

  File "/usr/lib/python2.3/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
    result = object(req)

  File "/usr/lib/python2.3/site-packages/mod_python/publisher.py", line 136, in handler
    result = util.apply_fs_data(object, req.form, req=req)

  File "/usr/lib/python2.3/site-packages/mod_python/util.py", line 361, in apply_fs_data
    return object(**args)

  File "/home/sites/phase2.newenergyfocus.com/web/do/ecco.py", line 269, in cview
    (listid, listcatid, itemid) = EccoViewAction.lookup_codes(listcode, catcode, itemcode)

  File "/home/sites/phase2.newenergyfocus.com/web/do/eccocms/EccoViewAction.py", line 328, in lookup_codes
    assert listid, "Non-existent list code specified! [%s]" % listcode

AssertionError: Non-existent list code specified! [Emissions]