Error 500 NAML exception in customized site: failed to connect

[LinJiangHan]

Hello, When I register at URLhttp://support.nabble.com/,its successful.// But in other Free forum by Nabble APP , I register ,All "Error 500 NAML exception in customized site: failed to connect".// How to solve this problem? // Thanks.// Error Message http://python.6.x6.nabble.com/template/NamlServlet.jtp?start_registration_page