Stripes Framework on WebSphere 8.x application server fails with FileNotFoundException

If you are struggling with running Stripes framework based application on IBM WebSphere application server 8.x I may help you. You probably end up with getting HTTP 403 error pages on every request. If you persuade your app server to give you some reasonable logging data (which is not easy in the world of Java application servers :/ ) you probably see FileNotFoundException logged during the request.
Here comes the explanation and a solution for you ...