Unable to "Deploy and Run" the first WebDynpro application

After succesfully deployment and running of the "Calculator" example (so the J2EE and SDM are working correctly), I tried to deploy the first WebDynpro application. My own developed WebDynpro didn't work so I tried it with the download of the solution of the example "WelcomeApp".

In the Internet browser (which starts http://perfect-1152:50000/webdynpro/dispatcher/local/Welcome/WelcomeApp) I get the following error:

"404 Not Found

The requested resource does not exist.

Details: Go to Main page of this site!"

When I go to the Main page I get the same error.

Any suggestions?