diff --git a/dashboard-parent/dashboard-widgets/dashboard-widgets-charts/src/main/java/org/wicketstuff/dashboard/widgets/charts/settings/HighChartsSettingsPanel.java b/dashboard-parent/dashboard-widgets/dashboard-widgets-charts/src/main/java/org/wicketstuff/dashboard/widgets/charts/settings/HighChartsSettingsPanel.java
index 398f96c74a..1c879a9e45 100644
--- a/dashboard-parent/dashboard-widgets/dashboard-widgets-charts/src/main/java/org/wicketstuff/dashboard/widgets/charts/settings/HighChartsSettingsPanel.java
+++ b/dashboard-parent/dashboard-widgets/dashboard-widgets-charts/src/main/java/org/wicketstuff/dashboard/widgets/charts/settings/HighChartsSettingsPanel.java
@@ -57,7 +57,7 @@ public HighChartsSettingsPanel(String id, IModel<HighChartsWidget> model) {
         form.add(new AjaxSubmitLink("submit") {
             private static final long serialVersionUID = 1L;
             @Override
-            protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
+            protected void onSubmit(AjaxRequestTarget target) {
                 getModelObject().getSettings().put(Settings.seriesType.name(), seriesType.name());
                 getModelObject().updateChart();
 
@@ -72,13 +72,15 @@ protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
                 HighChartsWidgetView widgetView = (HighChartsWidgetView) widgetPanel.getWidgetView();
                 target.add(widgetView);
             }
+
             @Override
-            protected void onError(AjaxRequestTarget target, Form<?> form) {
+            protected void onError(AjaxRequestTarget target) {
             }
         });
 
         form.add(new AjaxLink<Void>("cancel") {
             private static final long serialVersionUID = 1L;
+
             @Override
             public void onClick(AjaxRequestTarget target) {
                 hideSettingPanel(target);
diff --git a/dashboard-parent/dashboard-widgets/dashboard-widgets-jqplot/src/main/java/org/wicketstuff/dashboard/widgets/jqplot/JqPlotSettingsPanel.java b/dashboard-parent/dashboard-widgets/dashboard-widgets-jqplot/src/main/java/org/wicketstuff/dashboard/widgets/jqplot/JqPlotSettingsPanel.java
index 0345df52bd..9c67b73bbd 100644
--- a/dashboard-parent/dashboard-widgets/dashboard-widgets-jqplot/src/main/java/org/wicketstuff/dashboard/widgets/jqplot/JqPlotSettingsPanel.java
+++ b/dashboard-parent/dashboard-widgets/dashboard-widgets-jqplot/src/main/java/org/wicketstuff/dashboard/widgets/jqplot/JqPlotSettingsPanel.java
@@ -54,7 +54,7 @@ public JqPlotSettingsPanel(String id, IModel<JqPlotWidget> model) {
 			private static final long serialVersionUID = 1L;
 
 			@Override
-			protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
+			protected void onSubmit(AjaxRequestTarget target) {
             	getModelObject().getSettings().put("chartType", chartType);
 				Dashboard dashboard = findParent(DashboardPanel.class).getDashboard();
 				dashboardContext.getDashboardPersister().save(dashboard);
@@ -67,7 +67,7 @@ protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
 			}
 
 			@Override
-			protected void onError(AjaxRequestTarget target, Form<?> form) {
+			protected void onError(AjaxRequestTarget target) {
 			}
 
         });
diff --git a/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/ChartSettingsPanel.java b/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/ChartSettingsPanel.java
index d3c89d5b4a..794fecd9f1 100644
--- a/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/ChartSettingsPanel.java
+++ b/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/ChartSettingsPanel.java
@@ -54,7 +54,7 @@ public ChartSettingsPanel(String id, IModel<ChartWidget> model) {
 			private static final long serialVersionUID = 1L;
 
 			@Override
-			protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
+			protected void onSubmit(AjaxRequestTarget target) {
             	getModelObject().getSettings().put("chartType", chartType);
 				Dashboard dashboard = findParent(DashboardPanel.class).getDashboard();
 				dashboardContext.getDashboardPersister().save(dashboard);
@@ -67,7 +67,7 @@ protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
 			}
 
 			@Override
-			protected void onError(AjaxRequestTarget target, Form<?> form) {
+			protected void onError(AjaxRequestTarget target) {
 			}
 
         });
diff --git a/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/SWFObject.java b/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/SWFObject.java
index 2bfb0dee4f..d6dd9fd00f 100644
--- a/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/SWFObject.java
+++ b/dashboard-parent/dashboard-widgets/dashboard-widgets-ofchart/src/main/java/org/wicketstuff/dashboard/widgets/ofchart/SWFObject.java
@@ -14,6 +14,7 @@
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 
 import org.apache.wicket.Component;
 import org.apache.wicket.ajax.AjaxRequestTarget;
@@ -77,9 +78,9 @@ public String getJavaScript() {
 				flashUrl, id, width, height, version, "expressInstall.swf", parObj, attObj);
 
 		 // see http://old.nabble.com/Re%3A-Graphs%2C-Charts-and-Wicket-p21987222.html
-		AjaxRequestTarget target = RequestCycle.get().find(AjaxRequestTarget.class);
-		if (target != null) {
-			target.appendJavaScript(javascript);
+		Optional<AjaxRequestTarget> target = RequestCycle.get().find(AjaxRequestTarget.class);
+		if (target.isPresent()) {
+			target.get().appendJavaScript(javascript);
 		}
 		
 		return javascript;
diff --git a/dashboard-parent/pom.xml b/dashboard-parent/pom.xml
index deadb1980e..a5b9996dbe 100644
--- a/dashboard-parent/pom.xml
+++ b/dashboard-parent/pom.xml
@@ -31,8 +31,8 @@
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<slf4j.version>1.6.4</slf4j.version>
-		<log4j.version>1.2.16</log4j.version>
+		<slf4j.version>1.7.21</slf4j.version>
+		<log4j.version>1.2.17</log4j.version>
 	</properties>
 
 	<build>