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/PeerExtensionLoader.java
{
	/**
	 * The name of extension point.
	 */
	public static final String EXTENSION_POINT = "org.eclipse.birt.report.model.reportItemModel"; 
	private static final String ELEMENT_TAG = "reportItem"; 
	/**
	 * Constructs the extension loader for peer extension.
	 */
	public PeerExtensionLoader( )
	{
		super( EXTENSION_POINT );
	}
	/**
	 * Load one extension.
	 * 
	 * @param extension
	 *            one extension which extends the model extension point.
	 * @throws ExtensionException
	 *             if error is found when loading extension
	 * @throws MetaDataException
	 *             if error encountered when adding the element to metadata
	 *             dictionary.
	 */
	void loadExtension( IExtension extension ) throws ExtensionException,
			MetaDataException
	{
		IConfigurationElement[] configElements = extension
				.getConfigurationElements( );