@@ 3,10 3,13 @@ package com.civfanatics.civ3.xplatformed
 
 import static com.civfanatics.civ3.xplatformeditor.Main.fileChooserMode;
 import static com.civfanatics.civ3.xplatformeditor.Main.logger;
+import java.awt.EventQueue;
 import java.awt.FileDialog;
 import java.awt.Frame;
 import java.io.File;
 import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.util.concurrent.atomic.AtomicInteger;
 import javafx.application.Platform;
 import javafx.stage.DirectoryChooser;
 import javafx.stage.FileChooser;

          
@@ 105,19 108,31 @@ public class FileIO {
                     }
                 }
             }
-            int fileChoice = 0;
-            if (mode == FileDialog.SAVE) {
-                fileChoice = jfcBIQChooser.showSaveDialog(null);
+            
+            AtomicInteger fileChoiceAtomic = new AtomicInteger(0);
+            
+            //Must run on the Swing event thread.  On Mac in particular, but
+            //perhaps some other systems as well, the dialog will never appear
+            //if it is run on another thread.
+            try {
+                EventQueue.invokeAndWait(() -> {
+                    System.out.println("Showing Swing file chooser on thread " + Thread.currentThread().getName());
+                    if (mode == FileDialog.SAVE) {
+                        fileChoiceAtomic.set(jfcBIQChooser.showSaveDialog(null));
+                    }
+                    else if (buttonText == null) {
+                        fileChoiceAtomic.set(jfcBIQChooser.showOpenDialog(null));
+                    }
+                    else {
+                        fileChoiceAtomic.set(jfcBIQChooser.showDialog(null, buttonText));
+                    }
+                });
             }
-            else {
-                if (buttonText == null) {
-                    fileChoice = jfcBIQChooser.showOpenDialog(null);
-                }
-                else {
-                    fileChoice = jfcBIQChooser.showDialog(null, buttonText);
-                }
+            catch(InterruptedException | InvocationTargetException ex) {
+                logger.error("File chooser interrupted");
             }
-            if (fileChoice == JFileChooser.APPROVE_OPTION) {
+            
+            if (fileChoiceAtomic.get() == JFileChooser.APPROVE_OPTION) {
                 file = jfcBIQChooser.getSelectedFile();
                 if (!chooseDirectory) {
                     if (!(file.getName().toLowerCase().endsWith(".biq")) && !(file.getName().toLowerCase().endsWith(".sav")))

          
@@ 147,7 162,7 @@ public class FileIO {
                 };
                 Platform.runLater(runnable);
                 try {
-                    logger.info("Waiting for file chooser...");
+                    logger.info("Waiting for JavaFX file chooser...");
                     synchronized(runnable) {
                         runnable.wait();
                     }

          
@@ 256,7 271,7 @@ public class FileIO {
         };
         Platform.runLater(runnable);
         try {
-            logger.info("Waiting for file chooser...");
+            logger.info("Waiting for JavaFX file chooser...");
             synchronized(runnable) {
                 runnable.wait();
             }