diff --git a/src/main/java/org/fenix/llanfair/dialog/EditSettings.java b/src/main/java/org/fenix/llanfair/dialog/EditSettings.java
index fe49fff..6634ca1 100644
--- a/src/main/java/org/fenix/llanfair/dialog/EditSettings.java
+++ b/src/main/java/org/fenix/llanfair/dialog/EditSettings.java
@@ -8,10 +8,7 @@ import java.awt.event.WindowListener;
 import java.util.ArrayList;
 import java.util.List;
 
-import javax.swing.JButton;
-import javax.swing.JOptionPane;
-import javax.swing.JPanel;
-import javax.swing.JTabbedPane;
+import javax.swing.*;
 
 import org.fenix.llanfair.Language;
 import org.fenix.llanfair.config.Settings;
@@ -53,6 +50,7 @@ public class EditSettings extends LlanfairDialog
 		settingsTabs.add(new TabHistory());
 		settingsTabs.add(new TabComponents());
 
+		this.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
 		createResources();
 		placeComponents();
 		setPersistentBehavior();
@@ -121,10 +119,16 @@ public class EditSettings extends LlanfairDialog
 	public void actionPerformed(ActionEvent e) {
 		Object source = e.getSource();
 		if (source.equals(actionOK)) {
-			for (SettingsTab tab : settingsTabs) {
-				tab.doDelayedSettingChange();
+			try {
+				for (SettingsTab tab : settingsTabs) {
+					tab.doDelayedSettingChange();
+				}
+				dispose();
+			} catch (InvalidSettingException ex) {
+				ex.tab.requestFocusInWindow();
+				ex.field.requestFocusInWindow();
+				JOptionPane.showMessageDialog(this, ex.getMessage(), Language.ERROR.get(), JOptionPane.ERROR_MESSAGE);
 			}
-			dispose();
 		} else if (source.equals(reset)) {
 			int option = JOptionPane.showConfirmDialog(this,
 					"" + Language.WARN_RESET_SETTINGS);
@@ -144,10 +148,15 @@ public class EditSettings extends LlanfairDialog
 	@Override public void windowOpened(WindowEvent e) {}
 
 	@Override public void windowClosing(WindowEvent e) {
-		for (SettingsTab tab : settingsTabs) {
-			tab.doDelayedSettingChange();
+		try {
+			for (SettingsTab tab : settingsTabs) {
+				tab.doDelayedSettingChange();
+			}
+			dispose();
+		} catch (InvalidSettingException ex) {
+			ex.tab.grabFocus();
+			JOptionPane.showMessageDialog(this, ex.getMessage(), Language.ERROR.get(), JOptionPane.ERROR_MESSAGE);
 		}
-		dispose();
 	}
 
 }
diff --git a/src/main/java/org/fenix/llanfair/dialog/InvalidSettingException.java b/src/main/java/org/fenix/llanfair/dialog/InvalidSettingException.java
new file mode 100644
index 0000000..910cbf3
--- /dev/null
+++ b/src/main/java/org/fenix/llanfair/dialog/InvalidSettingException.java
@@ -0,0 +1,20 @@
+package org.fenix.llanfair.dialog;
+
+import java.awt.*;
+
+public class InvalidSettingException extends Exception {
+	public final SettingsTab tab;
+	public final Component field;
+
+	public InvalidSettingException(SettingsTab tab, Component field, String message) {
+		super(message);
+		this.tab = tab;
+		this.field = field;
+	}
+
+	public InvalidSettingException(SettingsTab tab, Component field, String message, Throwable cause) {
+		super(message, cause);
+		this.tab = tab;
+		this.field = field;
+	}
+}
diff --git a/src/main/java/org/fenix/llanfair/dialog/SettingsTab.java b/src/main/java/org/fenix/llanfair/dialog/SettingsTab.java
index 9cc7dc6..4cbd2c4 100644
--- a/src/main/java/org/fenix/llanfair/dialog/SettingsTab.java
+++ b/src/main/java/org/fenix/llanfair/dialog/SettingsTab.java
@@ -20,7 +20,7 @@ abstract class SettingsTab extends JPanel {
 		checkBoxes = new HashMap<String, SCheckBox>();
 	}
 
-	abstract void doDelayedSettingChange();
+	abstract void doDelayedSettingChange() throws InvalidSettingException;
 
 	protected class SCheckBox extends LinkedCheckBox {