Web Dynpro App

I am new to Web Dynpro, I have created a application which use BAPI_Goodsmvt_getdetail with 2 view, on to get the Material Doc and Year and then get the Item for the material docuement and show in Detail View.

I have used the Flight Example from Help.sap.com to create this application, I have able to deploy it on to my portal, but when I run this application it give me following message

500 Internal Server Error

Failed to process request. Please contact your system administrator.

I have installed a Sneak Preview on my laptop but it is not running the sdn server, how do I start sdm, so that I can test my application locally on my laptop.

Thanks

Jagraj dhillon