diff --git a/src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java b/src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java
index e8b161a2..809c15ea 100644
--- a/src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java
+++ b/src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java
@@ -140,7 +140,7 @@ public class ArbitraryDataFileManager extends Thread {
                     Long startTime = NTP.getTime();
                     ArbitraryDataFileMessage receivedArbitraryDataFileMessage = fetchArbitraryDataFile(peer, null, signature, hash, null);
                     Long endTime = NTP.getTime();
-                    if (receivedArbitraryDataFileMessage != null) {
+                    if (receivedArbitraryDataFileMessage != null && receivedArbitraryDataFileMessage.getArbitraryDataFile() != null) {
                         LOGGER.debug("Received data file {} from peer {}. Time taken: {} ms", receivedArbitraryDataFileMessage.getArbitraryDataFile().getHash58(), peer, (endTime-startTime));
                         receivedAtLeastOneFile = true;
 
diff --git a/src/main/java/org/qortal/gui/Gui.java b/src/main/java/org/qortal/gui/Gui.java
index 87342f6a..12191349 100644
--- a/src/main/java/org/qortal/gui/Gui.java
+++ b/src/main/java/org/qortal/gui/Gui.java
@@ -4,6 +4,7 @@ import java.awt.GraphicsEnvironment;
 import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ServiceConfigurationError;
 
 import javax.imageio.ImageIO;
 import javax.swing.JOptionPane;
@@ -46,12 +47,12 @@ public class Gui {
 		this.splashFrame = SplashFrame.getInstance();
 	}
 
-	protected static BufferedImage loadImage(String resourceName) {
+	protected static BufferedImage loadImage(String resourceName) throws IOException {
 		try (InputStream in = Gui.class.getResourceAsStream("/images/" + resourceName)) {
 			return ImageIO.read(in);
-		} catch (IllegalArgumentException | IOException e) {
+		} catch (IllegalArgumentException | IOException | ServiceConfigurationError e) {
 			LOGGER.warn(String.format("Couldn't locate image resource \"images/%s\"", resourceName));
-			return null;
+			throw new IOException(String.format("Couldn't locate image resource \"images/%s\"", resourceName));
 		}
 	}
 
diff --git a/src/main/java/org/qortal/gui/SplashFrame.java b/src/main/java/org/qortal/gui/SplashFrame.java
index c4ea51d0..3fd452fc 100644
--- a/src/main/java/org/qortal/gui/SplashFrame.java
+++ b/src/main/java/org/qortal/gui/SplashFrame.java
@@ -1,6 +1,7 @@
 package org.qortal.gui;
 
 import java.awt.*;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.awt.image.BufferedImage;
@@ -29,18 +30,23 @@ public class SplashFrame {
 		private JLabel statusLabel;
 
 		public SplashPanel() {
-			image = Gui.loadImage(defaultSplash);
+			try {
+				image = Gui.loadImage(defaultSplash);
+
+				// Add logo
+				JLabel imageLabel = new JLabel(new ImageIcon(image));
+				imageLabel.setSize(new Dimension(300, 300));
+				add(imageLabel);
+			}
+			catch (IOException e) {
+				LOGGER.warn("Unable to load splash panel image");
+			}
 
 			setOpaque(true);
 			setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
 			setBorder(new EmptyBorder(10, 10, 10, 10));
 			setBackground(Color.BLACK);
 
-			// Add logo
-			JLabel imageLabel = new JLabel(new ImageIcon(image));
-			imageLabel.setSize(new Dimension(300, 300));
-			add(imageLabel);
-
 			// Add spacing
 			add(Box.createRigidArea(new Dimension(0, 16)));
 
@@ -75,15 +81,20 @@ public class SplashFrame {
 
 		this.splashDialog = new JFrame();
 
-		List<Image> icons = new ArrayList<>();
-		icons.add(Gui.loadImage("icons/icon16.png"));
-		icons.add(Gui.loadImage("icons/qortal_ui_tray_synced.png"));
-		icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing_time-alt.png"));
-		icons.add(Gui.loadImage("icons/qortal_ui_tray_minting.png"));
-		icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing.png"));
-		icons.add(Gui.loadImage("icons/icon64.png"));
-		icons.add(Gui.loadImage("icons/Qlogo_128.png"));
-		this.splashDialog.setIconImages(icons);
+		try {
+			List<Image> icons = new ArrayList<>();
+			icons.add(Gui.loadImage("icons/icon16.png"));
+			icons.add(Gui.loadImage("icons/qortal_ui_tray_synced.png"));
+			icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing_time-alt.png"));
+			icons.add(Gui.loadImage("icons/qortal_ui_tray_minting.png"));
+			icons.add(Gui.loadImage("icons/qortal_ui_tray_syncing.png"));
+			icons.add(Gui.loadImage("icons/icon64.png"));
+			icons.add(Gui.loadImage("icons/Qlogo_128.png"));
+			this.splashDialog.setIconImages(icons);
+		}
+		catch (IOException e) {
+			LOGGER.warn("Unable to load splash frame icons");
+		}
 
 		this.splashPanel = new SplashPanel();
 		this.splashDialog.getContentPane().add(this.splashPanel);
diff --git a/src/main/java/org/qortal/gui/SysTray.java b/src/main/java/org/qortal/gui/SysTray.java
index 7a24f825..861c9ab0 100644
--- a/src/main/java/org/qortal/gui/SysTray.java
+++ b/src/main/java/org/qortal/gui/SysTray.java
@@ -61,7 +61,13 @@ public class SysTray {
 		this.popupMenu = createJPopupMenu();
 
 		// Build TrayIcon without AWT PopupMenu (which doesn't support Unicode)...
-		this.trayIcon = new TrayIcon(Gui.loadImage("icons/qortal_ui_tray_synced.png"), "qortal", null);
+		try {
+			this.trayIcon = new TrayIcon(Gui.loadImage("icons/qortal_ui_tray_synced.png"), "qortal", null);
+		}
+		catch (IOException e) {
+			LOGGER.warn("Unable to load system tray icon");
+			return;
+		}
 		// ...and attach mouse listener instead so we can use JPopupMenu (which does support Unicode)
 		this.trayIcon.addMouseListener(new MouseAdapter() {
 			@Override
diff --git a/src/main/java/org/qortal/transform/transaction/ArbitraryTransactionTransformer.java b/src/main/java/org/qortal/transform/transaction/ArbitraryTransactionTransformer.java
index c3190f03..b1554e8d 100644
--- a/src/main/java/org/qortal/transform/transaction/ArbitraryTransactionTransformer.java
+++ b/src/main/java/org/qortal/transform/transaction/ArbitraryTransactionTransformer.java
@@ -39,12 +39,12 @@ public class ArbitraryTransactionTransformer extends TransactionTransformer {
 	private static final int IDENTIFIER_SIZE_LENGTH = INT_LENGTH;
 	private static final int COMPRESSION_LENGTH = INT_LENGTH;
 	private static final int METHOD_LENGTH = INT_LENGTH;
-	private static final int SECRET_LENGTH = INT_LENGTH; // TODO: wtf?
+	private static final int SECRET_SIZE_LENGTH = INT_LENGTH;
 
 	private static final int EXTRAS_LENGTH = SERVICE_LENGTH + DATA_TYPE_LENGTH + DATA_SIZE_LENGTH;
 
 	private static final int EXTRAS_V5_LENGTH = NONCE_LENGTH + NAME_SIZE_LENGTH + IDENTIFIER_SIZE_LENGTH +
-			METHOD_LENGTH + SECRET_LENGTH + COMPRESSION_LENGTH + RAW_DATA_SIZE_LENGTH + METADATA_HASH_SIZE_LENGTH;
+			METHOD_LENGTH + SECRET_SIZE_LENGTH + COMPRESSION_LENGTH + RAW_DATA_SIZE_LENGTH + METADATA_HASH_SIZE_LENGTH;
 
 	protected static final TransactionLayout layout;