Starting the rudimentary log tracking. At this time, just exceptions.

app/gui-javafx/src/main/java/org/applecommander/javafx/FileStoreWindow.java

@@ -290,7 +290,32 @@ public class FileStoreWindow {
         Settings.setLastOpenedDirectory(selectedFile.getParentFile());
         Optional<Source> source = Sources.create(selectedFile);
         var inspected = FileStores.inspect(source.orElseThrow());
-        openFileStore(inspected.fileStores, true);
+        if (!inspected.fileStores.isEmpty()) {
+            openFileStore(inspected.fileStores, true);
+        }
+        else if (!inspected.messages.isEmpty()) {
+            Alert alert = new Alert(Alert.AlertType.WARNING);
+            alert.setTitle("Unable to open image");
+            alert.setHeaderText("Image format not recognized.");
+            StringBuilder content = new StringBuilder();
+            content.append("Errors occurred while opening image:\n");
+            inspected.messages.forEach(message -> {
+                content.append("* ").append(message.message()).append("\n");
+            });
+            alert.setContentText(content.toString());
+            Stage stage = (Stage) alert.getDialogPane().getScene().getWindow();
+            stage.setAlwaysOnTop(true);
+            alert.showAndWait();
+        }
+        else {
+            Alert alert = new Alert(Alert.AlertType.WARNING);
+            alert.setTitle("Unable to open image");
+            alert.setHeaderText("Image format not recognized.");
+            alert.setContentText("The image format was not recognized. No error occurred.");
+            Stage stage = (Stage) alert.getDialogPane().getScene().getWindow();
+            stage.setAlwaysOnTop(true);
+            alert.showAndWait();
+        }
     }
 
     public void openFileStore(List<FileStore> fileStores, boolean promptForWindow) {

lib/ac-api/src/main/java/org/applecommander/filestore/FileStoreFactory.java

@@ -63,6 +63,7 @@ public interface FileStoreFactory {
         public final Source source;
         public final NibbleTrackReaderWriter nibbleTrackReaderWriter;
         public final List<FileStore> fileStores = new ArrayList<>();
+        public final List<Message> messages = new ArrayList<>();
 
         public Context(Source source) {
             this.source = source;
@@ -215,4 +216,22 @@ public interface FileStoreFactory {
             }
         }
     }
+
+    record Message(Level level, String message) {
+        public static Message info(String fmt, Object... args) {
+            return new Message(Level.INFO, String.format(fmt, args));
+        }
+        public static Message warning(String fmt, Object... args) {
+            return new Message(Level.WARNING, String.format(fmt, args));
+        }
+        public static Message error(String fmt, Object... args) {
+            return new Message(Level.ERROR, String.format(fmt, args));
+        }
+    }
+
+    enum Level {
+        INFO,
+        WARNING,
+        ERROR
+    }
 }

lib/ac-api/src/main/java/org/applecommander/filestore/FileStores.java

@@ -57,7 +57,11 @@ public class FileStores {
             try {
                 factory.inspect(ctx);
             } catch (Throwable t) {
-                // ignore it
+                // Find the root cause
+                while (t.getCause() != null) {
+                    t = t.getCause();
+                }
+                ctx.messages.add(FileStoreFactory.Message.error(t.getMessage()));
             }
         });
         return ctx;