Bug 163018 An error extension will lead the report contain chart can't be opened and can not new a report.
Details: An error extension will lead the report contain chart can't open In org.eclipse.birt.report.tests.model has an error extension. When run the birt use workbenck, the report contain chart can't be opened and it can not new a report.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
/**
	 * The property is hidden in the property sheet.
	 */
	protected final static String HIDDEN_IN_PROPERTY_SHEET = "hide"; 
	/**
	 * The property is shown in the property sheet but readonly.
	 */
	protected final static String READONLY_IN_PROPERTY_SHEET = "readonly"; 
	/**
	 * Whether this definition represents an abstract element that the user
	 * normally does not see. Abstract elements exist to organize the element
	 * system.
	 */
	protected boolean abstractElement = false;
	/**
	 * The name of base element, if any, from which this element extends.
	 */
	protected String extendsFrom = null;
	/**
	 * The parent Element meta-data object (specified by the "extendsFrom"
	 * value).
	 */
	protected ElementDefn parent = null;
	/**
	 * specify if the element has a style.
	 */
	protected boolean hasStyle = false;
	/**
	 * Flag used when caching meta data.
	 */