Forgot to hand over the FXML loading to the new loader. Also, renamed the loader to be more descriptive of it's functionality.

src/main/java/com/sothr/imagetools/App.java

@@ -1,7 +1,7 @@
 package com.sothr.imagetools;
 
 import com.sothr.imagetools.errors.ImageToolsException;
-import com.sothr.imagetools.util.FileLoader;
+import com.sothr.imagetools.util.ResourceLoader;
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Parent;
@@ -13,8 +13,6 @@ import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.IOException;
-import java.net.URISyntaxException;
-import java.net.URL;
 import java.util.Properties;
 
 /**
@@ -71,9 +69,8 @@ public class App extends Application
     public void start(Stage primaryStage) throws Exception {
         logger.info("Image-Tools is starting");
         logger.info(String.format("Launching GUI with FXML file %s", MAINGUI_FXML));
-        ClassLoader cl = this.getClass().getClassLoader();
         try {
-            Parent root = FXMLLoader.load(cl.getResource(MAINGUI_FXML));
+            Parent root = FXMLLoader.load(ResourceLoader.get().getResource(MAINGUI_FXML));
             primaryStage.setScene(new Scene(root));
             //config main scene
             primaryStage.setTitle("Image Tools");

src/main/java/com/sothr/imagetools/util/FileLoader.java → src/main/java/com/sothr/imagetools/util/ResourceLoader.java

@@ -6,13 +6,13 @@ import java.net.URL;
 /**
  * Created by drew on 1/5/14.
  */
-public class FileLoader {
+public class ResourceLoader {
 
-    private static final FileLoader instance = new FileLoader();
+    private static final ResourceLoader instance = new ResourceLoader();
 
-    private FileLoader() {}
+    private ResourceLoader() {}
 
-    public static FileLoader get() {
+    public static ResourceLoader get() {
         return instance;
     }
 

src/main/scala/com/sothr/imagetools/ui/controller/AppController.scala

@@ -10,7 +10,7 @@ import javafx.scene.Group
 import javafx.scene.text.Text
 import java.io.{IOException, File}
 import java.util.Scanner
-import com.sothr.imagetools.util.FileLoader
+import com.sothr.imagetools.util.ResourceLoader
 import java.net.URL
 
 /**
@@ -30,7 +30,7 @@ class AppController {
     logger.debug("Displaying about screen")
     var aboutMessage = "Simple About Message"
     try {
-      aboutMessage = new Scanner(FileLoader.get().getResourceStream("documents/about")).useDelimiter("\\A").next()
+      aboutMessage = new Scanner(ResourceLoader.get().getResourceStream("documents/about")).useDelimiter("\\A").next()
     } catch {
       case ioe:IOException =>
         logger.error("Unable to read about file")