There are some architectural differences between coding with Java and coding with My webMethods Server. You must keep the following in mind when you call Application Platform services from My webMethods Server services:

When you develop My webMethods Server user interface applications that call Application Platform services, you must ensure that the Application Platform service classes are not accessed from any code that is executed during the web context initialization of the My webMethods Server user interface project, which occurs when the project is published. The service project cannot be installed in the container runtime until after the user interface project is initialized, which leads to exceptions of type “ClassDefNotFoundException.”