Show the error message from the server on an account creation attempt

resources/languages/resources.properties

@@ -997,7 +997,7 @@ plugin.jabberaccregwizz.RESOURCE=Resource
 plugin.jabberaccregwizz.AUTORESOURCE=Auto generate resource
 plugin.jabberaccregwizz.PRIORITY=Priority
 plugin.jabberaccregwizz.XMPP_ERROR=XMPP Error
-plugin.jabberaccregwizz.UNKNOWN_XMPP_ERROR=Unknown XMPP error. Verify that the server name is correct.
+plugin.jabberaccregwizz.UNKNOWN_XMPP_ERROR=Unknown XMPP error ({0}). Verify that the server name is correct.
 plugin.jabberaccregwizz.NOT_SAME_PASSWORD=Your passwords did not match.
 plugin.jabberaccregwizz.OVERRIDE_SERVER_DEFAULT_OPTIONS=Override server default options
 plugin.jabberaccregwizz.ADVANCED_OPTIONS=Advanced options

src/net/java/sip/communicator/plugin/jabberaccregwizz/JabberAccountCreationForm.java

@@ -168,6 +168,7 @@ private boolean createJabberAccount(String server, int port, String username,
         }
         catch (XMPPException exc)
         {
+            logger.error(exc);
             if (exc.getXMPPError().getCode() == 409)
             {
                 showErrorMessage(Resources.getString(
@@ -179,9 +180,12 @@ private boolean createJabberAccount(String server, int port, String username,
             }
             else
             {
-                showErrorMessage(Resources.getString(
+                showErrorMessage(Resources.getResources().getI18NString(
-                        "plugin.jabberaccregwizz.UNKNOWN_XMPP_ERROR"));
+                        "plugin.jabberaccregwizz.UNKNOWN_XMPP_ERROR",
+                        new String[]{exc.getMessage()}
+                    ));
             }
+
             return false;
         }
     }
@@ -274,7 +278,9 @@ private void showErrorMessage(String text)
         if (errorPane.getParent() == null)
             userIDPassPanel.add(errorPane, BorderLayout.NORTH);
 
-        SwingUtilities.getWindowAncestor(this).pack();
+        Window ancestor = SwingUtilities.getWindowAncestor(this);
+        if (ancestor != null)
+            ancestor.pack();
     }
 
     /**