diff --git a/src/main/java/ch/zhaw/gartenverwaltung/MyScheduleController.java b/src/main/java/ch/zhaw/gartenverwaltung/MyScheduleController.java
index 43eeb4c..df31cb9 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/MyScheduleController.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/MyScheduleController.java
@@ -24,6 +24,7 @@ import javafx.scene.layout.VBox;
 import java.io.IOException;
 import java.time.LocalDate;
 import java.util.List;
+import java.util.Objects;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -208,6 +209,12 @@ public class MyScheduleController {
         alert.setHeaderText("Are you sure you have completed this task?");
         alert.setContentText("Confirming that you have completed the task will remove it from the schedule.");
 
+        DialogPane dialogPane = alert.getDialogPane();
+
+        dialogPane.getStylesheets().add(
+                Objects.requireNonNull(getClass().getResource("bootstrap/dialogStyle.css")).toExternalForm());
+        dialogPane.getStyleClass().add("myDialog");
+
         alert.showAndWait()
                 .ifPresent(buttonType -> {
                     if (buttonType == ButtonType.OK) {
diff --git a/src/main/java/ch/zhaw/gartenverwaltung/TutorialController.java b/src/main/java/ch/zhaw/gartenverwaltung/TutorialController.java
index 2e0b1db..521a3bc 100644
--- a/src/main/java/ch/zhaw/gartenverwaltung/TutorialController.java
+++ b/src/main/java/ch/zhaw/gartenverwaltung/TutorialController.java
@@ -7,6 +7,7 @@ import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.StackPane;
 import javafx.stage.Stage;
+import java.io.File;
 
 /**
  * Controller class for the Tutorial.fxml file
@@ -32,17 +33,27 @@ public class TutorialController {
         switchViews();
         setButtonAbilities();
 
-        Image addNewPlantImage = new Image(String.valueOf(PlantsController.class.getResource("add-new-plant.png")));
-        Image selectSowHarvestImage = new Image(String.valueOf(PlantsController.class.getResource("select-sow-harvest.png")));
-        Image scheduleImage = new Image(String.valueOf(PlantsController.class.getResource("schedule.png")));
-        Image detailDeleteButtonsImage = new Image(String.valueOf(PlantsController.class.getResource("details-delete.png")));
-        Image addTaskImage = new Image(String.valueOf(PlantsController.class.getResource("add-task.png")));
+        setImageView(imgAddNewPlant, "add-new-plant.png");
+        setImageView(imgSelectDate, "select-sow-harvest.png");
+        setImageView(imgDetailDeleteButtons, "details-delete.png");
+        setImageView(imgTaskList, "schedule.png");
+        setImageView(imgAddTaskButton, "add-task.png");
+    }
 
-        imgAddNewPlant.setImage(addNewPlantImage);
-        imgSelectDate.setImage(selectSowHarvestImage);
-        imgDetailDeleteButtons.setImage(detailDeleteButtonsImage);
-        imgAddTaskButton.setImage(addTaskImage);
-        imgTaskList.setImage(scheduleImage);
+    /**
+     * update the given image view with screenshot or placeholder image.
+     * @param imageView the image view to update
+     * @param fileName the file name of the source
+     */
+    private void setImageView(ImageView imageView, String fileName) {
+        File file = new File(String.valueOf(PlantsController.class.getResource(fileName)));
+        Image image;
+        if (file.exists()) {
+            image = new Image(String.valueOf(PlantsController.class.getResource(fileName)));
+        } else {
+            image = new Image(String.valueOf(PlantsController.class.getResource("placeholder.png")));
+        }
+        imageView.setImage(image);
     }
 
     public void viewNextPage() {
diff --git a/src/main/resources/ch/zhaw/gartenverwaltung/Tutorial.fxml b/src/main/resources/ch/zhaw/gartenverwaltung/Tutorial.fxml
index 93bb2d0..ae25ce8 100644
--- a/src/main/resources/ch/zhaw/gartenverwaltung/Tutorial.fxml
+++ b/src/main/resources/ch/zhaw/gartenverwaltung/Tutorial.fxml
@@ -14,7 +14,7 @@
 <?import javafx.scene.text.Text?>
 <?import javafx.scene.text.TextFlow?>
 
-<BorderPane maxHeight="470.0" maxWidth="724.0" minHeight="470.0" minWidth="724.0" prefHeight="470.0" prefWidth="724.0" xmlns="http://javafx.com/javafx/19" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.TutorialController">
+<BorderPane maxHeight="470.0" maxWidth="724.0" minHeight="470.0" minWidth="724.0" prefHeight="470.0" prefWidth="724.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.TutorialController">
    <bottom>
       <HBox alignment="CENTER" prefHeight="0.0" prefWidth="724.0" BorderPane.alignment="CENTER">
          <children>