Fix

app.py

@@ -865,6 +865,8 @@ def _on_video_change_pointbox(state: AppState, video: str | dict) -> tuple[AppSt
 
 
 def _on_video_change_text(state: AppState, video: str | dict) -> tuple[AppState, dict, Image.Image, str, str]:
+    if video is None:
+        return state, None, None, None, None
     state, min_idx, max_idx, first_frame, status = init_video_session(state, video, "text")
     active_prompts = _get_active_prompts_display(state)
     return (