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
if ( "true".equalsIgnoreCase( isList ) ) 
						extPropDefn.setIsList( true );
					else
						extPropDefn.setIsList( false );
					extPropDefn.setDetails( detailType );
					break;
			}
			
			if ( !StringUtil.isBlank( defaultValue ) )
			{
				try
				{
					Object value = extPropDefn.validateXml( null, defaultValue );
					extPropDefn.setDefault( value );
				}
				catch ( PropertyValueException e )
				{
					throw new ExtensionException(
							new String[]{name, elementDefn.getName( )},
							MetaDataException.DESIGN_EXCEPTION_INVALID_DEFAULT_VALUE );
				}
			}
			return extPropDefn;
		}
		/**
		 * Loads one property definition of the given element.
		 * 
		 * @param elementTag
		 *            the element tag