Error during filepolling.

Whenever i try to enable filepolling, i get this error

ServiceVCmnAdmin.ports:restoreStatusErrorclass com.wm.app.b2b.server.ServiceException [ISS.0086.9020] Additional Files/admin_dsp_ports.xml does not existServiceVCmnAdmin.ports:restoreStatusErrorclass com.wm.app.b2b.server.ServiceException [ISS.0086.9020] Additional Files/admin_dsp_ports.xml does not exist

Is this a mandatory for webmethods or custom file?