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
* represented by the {@link SystemPropertyDefn}and
 * {@link org.eclipse.birt.report.model.api.core.UserPropertyDefn}classes.
 * 
 * <h3>Element Inheritance</h3>
 * 
 * Elements inherit from one another. There are two subtly different forms of
 * inheritance used in the system. First, the definition of element types uses
 * inheritance to simplify the description of the set of element types. For
 * example, the Data and Label elements are both types of the ReportItem
 * element.
 * <p>
 * Inheritance in the type system is described in this class (ElementDefn). Such
 * inheritance is constant for all designs. Type system inheritance, by
 * definition, allows one type of element to inherit from another.
 * <p>
 * Like any OO hierarchy, the element type system starts with certain abstract
 * base types such as ReportElement or ReportItem. While these are important for
 * describing the type system, they are irrelevant (or worse, confusing) to the
 * user. Thus, they are private to the implementation and not generally visible
 * to the user. (It is not a secret that they exist -- the XML design format is
 * open -- but it is not relevant to the business of building a report.) Such
 * elements are marked as abstract.
 * <p>
 * The second form of inheritance is defined by the user. A user can define a
 * Label, for example, that has many special attributes. The user can then
 * create other labels that derive from the first. User-defined inheritance is
 * subtly different from type-system inheritance. User cannot define new element
 * types; they can only set properties and customize existing types.
 * <p>
 * Said another way, type system inheritance uses Java-like class inheritance.