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
import org.eclipse.birt.report.model.api.metadata.IElementDefn;
import org.eclipse.birt.report.model.api.metadata.IElementPropertyDefn;
import org.eclipse.birt.report.model.api.metadata.IPropertyDefn;
import org.eclipse.birt.report.model.api.metadata.IPropertyType;
import org.eclipse.birt.report.model.api.metadata.ISlotDefn;
import org.eclipse.birt.report.model.api.metadata.MetaDataConstants;
import org.eclipse.birt.report.model.api.util.StringUtil;
import org.eclipse.birt.report.model.api.validators.StyleReferenceValidator;
import org.eclipse.birt.report.model.api.validators.UnsupportedElementValidator;
import org.eclipse.birt.report.model.core.DesignElement;
import org.eclipse.birt.report.model.elements.interfaces.IStyledElementModel;
import org.eclipse.birt.report.model.validators.AbstractSemanticValidator;
/**
 * Describes a report element. This class represents "meta-data" about an
 * element. This class does not represent the element itself. Rather, it
 * describes a "class" of elements. The definition provides information about
 * the set of valid properties, their validation rules, and more.
 * <p>
 * To understand this class, it helps to understand some concepts behind the
 * design of the model.
 * 
 * <h3>Meta-data vs. Elements</h3>
 * 
 * A design is made up of <em>elements</em>. BIRT defines a fixed-set of
 * <em>element types</em> such as List or Data or Image. The user defines the
 * elements in the report. However, element types are defined by the development
 * team and are fixed for any given release of the product. The class
 * DesignElement (and its subclasses) describe the elements that users create.
 * The class ElementDefn describes element types.
 * <p>