diff --git a/app/src/processing/app/contrib/ContributionTab.java b/app/src/processing/app/contrib/ContributionTab.java
index f32821356..b9c4529a7 100644
--- a/app/src/processing/app/contrib/ContributionTab.java
+++ b/app/src/processing/app/contrib/ContributionTab.java
@@ -52,7 +52,7 @@ public class ContributionTab {
   JButton restartButton;
   JLabel categoryLabel;
   JLabel loaderLabel;
-  
+
   JPanel errorPanel;
   JTextPane errorMessage;
   JButton tryAgainButton;
@@ -62,7 +62,7 @@ public class ContributionTab {
   Editor editor;
   String category;
   ContributionListing contribListing;
-  
+
   JProgressBar progressBar;
 
 
@@ -112,8 +112,8 @@ public class ContributionTab {
 //    panel.add(filler);
 //    return panel;
 //  }
-  
-  
+
+
 
 
   public void showFrame(final Editor editor, boolean activateErrorPanel,
@@ -140,7 +140,7 @@ public class ContributionTab {
       loaderLabel.setOpaque(false);
       loaderLabel.setBackground(Color.WHITE);
     }
-    
+
     /*restartButton = new JButton(Language.text("contrib.restart"));
     restartButton.setVisible(false);
     restartButton.addActionListener(new ActionListener() {
@@ -188,7 +188,7 @@ public class ContributionTab {
 
     });*/
 
- 
+
     GroupLayout layout = new GroupLayout(panel);
     panel.setLayout(layout);
     layout.setAutoCreateContainerGaps(true);
@@ -214,7 +214,7 @@ public class ContributionTab {
  }
 
 
-  /** Creates and arranges the Swing components in the dialog. 
+  /** Creates and arranges the Swing components in the dialog.
    */
   private void createComponents() {
 
@@ -222,9 +222,9 @@ public class ContributionTab {
 
       categoryChooser = new JComboBox<String>();
       categoryChooser.setMaximumRowCount(20);
-      
+
       updateCategoryChooser();
-      
+
       categoryChooser.addItemListener(new ItemListener() {
         public void itemStateChanged(ItemEvent e) {
           category = (String) categoryChooser.getSelectedItem();
@@ -237,9 +237,9 @@ public class ContributionTab {
       });
 
       filterField = new FilterField();
-      
+
       buildErrorPanel();
-     
+
   }
   private void buildErrorPanel(){
     errorPanel = new JPanel();
@@ -254,17 +254,17 @@ public class ContributionTab {
       + "Please verify your network connection again, then try connecting again.");
     errorMessage.setMaximumSize(new Dimension(450, 50));
     errorMessage.setOpaque(false);
-    
+
     StyledDocument doc = errorMessage.getStyledDocument();
     SimpleAttributeSet center = new SimpleAttributeSet();
     StyleConstants.setAlignment(center, StyleConstants.ALIGN_CENTER);
     doc.setParagraphAttributes(0, doc.getLength(), center, false);
-    
-    
+
+
     closeButton = new JButton("X");
     closeButton.setOpaque(false);
     closeButton.addActionListener(new ActionListener() {
-      
+
       @Override
       public void actionPerformed(ActionEvent e) {
         contributionManagerDialog.makeAndShowTab(false, false);
@@ -272,7 +272,7 @@ public class ContributionTab {
     });
     tryAgainButton = new JButton("Try Again");
     tryAgainButton.addActionListener(new ActionListener() {
-      
+
       @Override
       public void actionPerformed(ActionEvent e) {
         contributionManagerDialog.makeAndShowTab(false, true);
@@ -307,11 +307,12 @@ public class ContributionTab {
 //      }
       Collections.sort(categories);
 //    categories.add(0, ContributionManagerDialog.ANY_CATEGORY);
+      @SuppressWarnings("unused")
       boolean categoriesFound = false;
       categoryChooser.addItem(ContributionManagerDialog.ANY_CATEGORY);
       for (String s : categories) {
         categoryChooser.addItem(s);
-        if (!s.equals("Unknown")) {
+        if (!s.equals(Contribution.UNKNOWN_CATEGORY)) {
           categoriesFound = true;
         }
       }
@@ -372,7 +373,7 @@ public class ContributionTab {
   }
 
 
- 
+
 
   protected void setFilterText(String filter) {
     if (filter == null || filter.isEmpty()) {
diff --git a/app/src/processing/app/contrib/ModeContribution.java b/app/src/processing/app/contrib/ModeContribution.java
index 53385b118..9ed1c2672 100644
--- a/app/src/processing/app/contrib/ModeContribution.java
+++ b/app/src/processing/app/contrib/ModeContribution.java
@@ -28,13 +28,11 @@ import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 
 import processing.app.Base;
 import processing.app.Mode;
-import processing.app.contrib.LocalContribution.IgnorableException;
 
 
 public class ModeContribution extends LocalContribution {
@@ -180,9 +178,9 @@ public class ModeContribution extends LocalContribution {
     ModeContribution other = (ModeContribution) o;
     return loader.equals(other.loader) && mode.equals(other.getMode());
   }
-  
+
   public String initLoader(Base base, String className) throws Exception {
-    
+
     File modeDirectory = new File(folder, getTypeName());
     if (modeDirectory.exists()) {
       Base.log("checking mode folder regarding " + className);
@@ -202,18 +200,18 @@ public class ModeContribution extends LocalContribution {
                                        " class inside " + mainJar.getAbsolutePath());
         }
       }
-      
+
       ArrayList<URL> extraUrls = new ArrayList<>();
       if (imports != null && imports.size() > 0) {
         // if the mode has any dependencies (defined as imports in mode.properties),
         // add the dependencies to the classloader
-        
+
         HashMap<String, Mode> installedModes = new HashMap<>();
         for(Mode m: base.getModeList()){
           // Base.log("Mode contrib: " + m.getClass().getName() + " : "+ m.getFolder());
           installedModes.put(m.getClass().getName(), m);
         }
-        
+
         for(String modeImport: imports){
           if (installedModes.containsKey(modeImport)) {
             Base.log("Found mode dependency " + modeImport);
@@ -237,13 +235,13 @@ public class ModeContribution extends LocalContribution {
       if (archives != null && archives.length > 0) {
         int arrLen = archives.length + extraUrls.size();
         URL[] urlList = new URL[arrLen];
-        
+
         int j = 0;
         for (; j < extraUrls.size(); j++) {
           //Base.log("Found archive " + archives[j] + " for " + getName());
           urlList[j] = extraUrls.get(j);
         }
-        
+
         for (int k = 0; k < archives.length; k++,j++) {
           Base.log("Found archive " + archives[k] + " for " + getName());
           urlList[j] = archives[k].toURI().toURL();