If an expression you evaluate causes a runtime exception, the exception will be reported in the editor. For example:
Type and select the expression
Object x = null; x.toString() in the editor and click Display in the toolbar.
The error message:
An exception occurred during evaluation: java.lang.NullPointerException
will be displayed in the editor.
Displaying the result of evaluating an expression
Inspecting the result of evaluating an expression
Executing an expression