diff --git a/.player_heartbeat b/.player_heartbeat
deleted file mode 100644
index cf307dd..0000000
--- a/.player_heartbeat
+++ /dev/null
@@ -1 +0,0 @@
-1768680348.358552
\ No newline at end of file
diff --git a/src/edit_popup.py b/src/edit_popup.py
index fbaa2b8..ec04072 100644
--- a/src/edit_popup.py
+++ b/src/edit_popup.py
@@ -331,13 +331,15 @@ class EditPopup(Popup):
                                        new_version if version_match else 1, output_filename)
                     
                     # Upload to server in background (continues after popup closes)
+                    # TEMPORARILY DISABLED: background thread was causing app crashes during playback
+                    # TODO: Re-enable with proper thread safety and separate thread pool
                     upload_thread = threading.Thread(
                         target=self._upload_to_server,
                         args=(output_path, json_filename),
                         daemon=True
                     )
-                    upload_thread.start()
-                    Logger.info(f"EditPopup: Background upload thread started")
+                    # upload_thread.start()  # DISABLED FOR TESTING
+                    Logger.info(f"EditPopup: Background upload thread DISABLED (testing stability)")
                     
                     # NOW show saving popup AFTER everything is done
                     def show_saving_and_dismiss(dt):