Getting Started with the Debugger 
Prerequisites
To debug a model, it must be deployed to the SAP system configured in 
Window 
Preferences SAP AS Java 
.
Procedure
Starting a debug session launches the runtime application in debug mode, adds the debug session to Debug View, and the application is executed until it reaches a breakpoint.
You can start to debug a model in one of the following ways:
Right click the model in the Model Browser view, and choose Debug.
Use a debug launch configuration, which specifies which model to debug.
Creating a Debug Launch Configuration
A debug launch configuration enables you to create a configuration that launches a Visual Composer application in debug mode.
To create a debug launch configuration:
In the Debug perspective, choose
Run Debug Configurations .In the left pane, select Visual Composer.
Click the
(New launch configuration) button.The right pane displays the configuration details.
In the Name field, specify a name for the configuration.
In the Main tab, select the model to debug.
In the General tab, you can set additional optional configurations:
Display in
Browser: Opens the runtime application in the default browser defined on your machine.
Window: Opens the runtime application in a thin view of the browser that does not include the browser toolbars and add-ons. This view prevents undesired use of the browser toolbar buttons (Back/Forward/Refresh). In addition, this view supports automatic context switch from SAP NetWeaver Developer Studio to the runtime application when user input is required. This functionality is not supported in the Browser option.
Application Start
Breakpoint on first step: Stops the application at the first step.
After creating a configuration, you can launch it either by using the Debug Configurations dialog box or the Debug button in the toolbar.
Stopping a Debug Session
Stopping a debug session closes the launched application being debugged, and removes the debug session from Debug View.
To stop a debug session:
In Debug View, select the debugged application to stop.
Click the
(Terminate) button on the Debug View toolbar.