Bug 173236 NPE is thrown when opening a design file that is created by a higher version BIRT
1. New a report, switch to xml-source view. 2. Edit the version number in line 2, from 3.2.10 to 3.2.11 and save. 3. Close the report and reopen it. The xml-source view is opened automatically. Switch to lay-out view, there's an error message window, and NPE is thrown in error-log view. When user is trying to open a design file that is created by a higher version BIRT, model will throw an exception and stop parsing the report design file. UI should 1. Prevent the NPE 2. Telling user that he is using a higher version design file that this build does not support. (Catch the exception and reflect the message in the exception to end user)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ErrorDetail.java
private String validationID;
	/**
	 * The reference to the editor.For example graphic editor, xml source
	 * editor, script editor and so on.
	 * 
	 */
	private String subEditor = null;
	/**
	 * The error description, which is used for <code>toString()</code>.
	 * Generally, it's only used for debug purposes.
	 */
	private StringBuffer description = new StringBuffer( );
	/**
	 * The default constructor.
	 * 
	 */
	private ErrorDetail( )
	{
	}
	/**
	 * Constructs the error detail with a given exception.
	 * 
	 * @param e
	 *            the exception types that can be translated are
	 *            <code>XMLParserException</code>,
	 *            <code>DesignParserException</code>,
	 *            <code>SemanticException</code> , <code>SAXException</code>.
	 */
	public ErrorDetail( Exception e )
	{