Validating the Application Model
You can check whether all of your definitions for the application model are valid. Your model is invalid, for example, if a name you specified contains special characters that are not allowed or if a required property has not yet been defined.
If one or more errors are detected, the number of errors is indicated in a message at the top of the Outline Editor, for example, "9 errors detected". When you move the mouse pointer over this message, a tooltip appears informing you what to have to do to fix the errors.
Mobile Development automatically validates an application model when you save your changes to it. In the case of a name, it even checks the characters while you enter them. However, you can also validate the application model manually at any time you want by clicking a toolbar button as described below.
To validate the application model manually
2. Click 
Validate Application Model which is shown in the toolbar of the Outline Editor. 3. Check the area to the left of the Outline Editor's toolbar to see whether errors have been detected.
