The Error: ADMA5060E: Resource validation for application <app_name> failed due to unexpected exception java.lang.NullPointerException
Often occurs when you have coded attributes for a deployment to build an attribute string for an AdminApp.install for example
'-target', 'WebSphere:node=WAS7_01_AppServer01 ,server=server1',
The line above has a space after the node name, it should be as follows
'-target', 'WebSphere:node=WAS7_01_AppServer01,server=server1',
Notice I have removed the space after WAS7_01_AppServer01