diff --git a/Kieker.WebGUI/src/main/java/kieker/webgui/beans/view/CurrentAnalysisEditorBean.java b/Kieker.WebGUI/src/main/java/kieker/webgui/beans/view/CurrentAnalysisEditorBean.java
index 5f211f539983f2772ba473b2750b6e08d0625d7a..6154d015b7b02ee9bd098f00da9fb24a913f3d1a 100644
--- a/Kieker.WebGUI/src/main/java/kieker/webgui/beans/view/CurrentAnalysisEditorBean.java
+++ b/Kieker.WebGUI/src/main/java/kieker/webgui/beans/view/CurrentAnalysisEditorBean.java
@@ -879,17 +879,23 @@ public final class CurrentAnalysisEditorBean {
 	 *            The class of the repository to be added.
 	 */
 	public void addRepository(final Class<AbstractRepository> clazz) {
-		// Create a new instance for the model
-		final MIRepository repository = this.factory.createRepository();
-		repository.setClassname(clazz.getName());
-		repository.setName(clazz.getSimpleName());
+		try {
+			// Create a new instance for the model
+			final MIRepository repository = this.factory.createRepository();
+			repository.setClassname(clazz.getName());
+			repository.setName(clazz.getSimpleName());
 
-		this.fillProperties(clazz, repository);
-		synchronized (this) {
-			// Add it to the project - and to the graph
-			this.project.getRepositories().add(repository);
-			this.currentAnalysisEditorGraphBean.addRepository(repository);
-			this.currentAnalysisEditorGraphBean.refreshGraph();
+			this.fillProperties(clazz, repository);
+			synchronized (this) {
+				// Add it to the project - and to the graph
+				this.project.getRepositories().add(repository);
+				this.currentAnalysisEditorGraphBean.addRepository(repository);
+				this.currentAnalysisEditorGraphBean.refreshGraph();
+			}
+		} catch (final NoClassDefFoundError ex) {
+			// This exception can occur if (for example) a class is missing
+			CurrentAnalysisEditorBean.showMessage(FacesMessage.SEVERITY_ERROR, "An error occured during the creation of the repository. Check the dependencies.");
+			CurrentAnalysisEditorBean.LOG.error("An error occured during the creation of the repository. Check the dependencies.", ex);
 		}
 	}
 
@@ -900,31 +906,37 @@ public final class CurrentAnalysisEditorBean {
 	 *            The class of the plugin to be added. This can be both, a filter or a reader.
 	 */
 	public void addPlugin(final Class<AbstractPlugin> clazz) {
-		// Create a new instance for the model
-		final MIPlugin plugin;
-		if (this.classAndMethodContainer.getAbstractReaderPluginClass().isAssignableFrom(clazz)) {
-			plugin = this.factory.createReader();
-		} else {
-			plugin = this.factory.createFilter();
-		}
-		plugin.setClassname(clazz.getName());
-		plugin.setName(clazz.getSimpleName());
+		try {
+			// Create a new instance for the model
+			final MIPlugin plugin;
+			if (this.classAndMethodContainer.getAbstractReaderPluginClass().isAssignableFrom(clazz)) {
+				plugin = this.factory.createReader();
+			} else {
+				plugin = this.factory.createFilter();
+			}
+			plugin.setClassname(clazz.getName());
+			plugin.setName(clazz.getSimpleName());
 
-		this.fillProperties(clazz, plugin);
-		this.fillPorts(clazz, plugin);
-		this.fillDisplays(clazz, plugin);
+			this.fillProperties(clazz, plugin);
+			this.fillPorts(clazz, plugin);
+			this.fillDisplays(clazz, plugin);
 
-		synchronized (this) {
-			// Add it to the project
-			this.project.getPlugins().add(plugin);
+			synchronized (this) {
+				// Add it to the project
+				this.project.getPlugins().add(plugin);
 
-			// Add the element to the graph
-			if (plugin instanceof MIReader) {
-				this.currentAnalysisEditorGraphBean.addReader((MIReader) plugin);
-			} else {
-				this.currentAnalysisEditorGraphBean.addFilter((MIFilter) plugin);
+				// Add the element to the graph
+				if (plugin instanceof MIReader) {
+					this.currentAnalysisEditorGraphBean.addReader((MIReader) plugin);
+				} else {
+					this.currentAnalysisEditorGraphBean.addFilter((MIFilter) plugin);
+				}
+				this.currentAnalysisEditorGraphBean.refreshGraph();
 			}
-			this.currentAnalysisEditorGraphBean.refreshGraph();
+		} catch (final NoClassDefFoundError ex) {
+			// This exception can occur if (for example) a class is missing
+			CurrentAnalysisEditorBean.showMessage(FacesMessage.SEVERITY_ERROR, "An error occured during the creation of the plugin. Check the dependencies.");
+			CurrentAnalysisEditorBean.LOG.error("An error occured during the creation of the plugin. Check the dependencies.", ex);
 		}
 	}