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
continue;
				SystemPropertyDefn prop = (SystemPropertyDefn) style
						.getProperty( propName );
				
				
				
				
				
				
				if ( prop == null )
					throw new MetaDataException(
							new String[]{propName, name},
							MetaDataException.DESIGN_EXCEPTION_STYLE_PROP_NOT_FOUND );
				assert prop.isStyleProperty( );
				
				
				properties.put( prop.getName( ), prop );
			}
		}
	}
	/**
	 * Builds the meta-data for each slotID in this container element.
	 * 
	 * @throws MetaDataException
	 *             if build of any slot failed.
	 */
	protected void buildSlots( ) throws MetaDataException
	{
		if ( slots != null && slots.size( ) == 0 )
			slots = null;