Nested Portlets Portlet is a property in the portal.properties file, which is the default configuration file for Sun GlassFish Web Space Server. You can override this property using portal-ext.properties file.
nested.portlets.layout.template.default=2_columns_i |
Add a comma separated list of layout templateIDs that should not be allowed in the Nested Portlets Portlet.
nested.portlets.layout.template.unsupported=freeform,1_column |