To reproduce this issue, just run
jupyter nblassic picca@page:~$ jupyter nbclassic [W 2025-05-21 08:35:39.406 ServerApp] A `_jupyter_server_extension_points` function was not found in nbclassic. Instead, a `_jupyter_server_extension_paths` function was found and will be used for now. This function name will be deprecated in future releases of Jupyter Server. [W 2025-05-21 08:35:39.411 ServerApp] A `_jupyter_server_extension_points` function was not found in notebook_shim. Instead, a `_jupyter_server_extension_paths` function was found and will be used for now. This function name will be deprecated in future releases of Jupyter Server. [I 2025-05-21 08:35:39.414 ServerApp] jupyter_server_terminals | extension was successfully linked. [I 2025-05-21 08:35:39.563 ServerApp] nbclassic | extension was successfully linked. [I 2025-05-21 08:35:39.565 ServerApp] notebook_shim | extension was successfully linked. [I 2025-05-21 08:35:39.625 ServerApp] notebook_shim | extension was successfully loaded. [I 2025-05-21 08:35:39.626 ServerApp] jupyter_server_terminals | extension was successfully loaded. [I 2025-05-21 08:35:39.629 ServerApp] nbclassic | extension was successfully loaded. [I 2025-05-21 08:35:39.632 ServerApp] Serving notebooks from local directory: /home/picca [I 2025-05-21 08:35:39.632 ServerApp] Jupyter Server 2.15.0 is running at: [I 2025-05-21 08:35:39.632 ServerApp] http://localhost:8888/tree?token=5990de7375c2b246397260a5e97acc68a73c7d20bd1fd67c [I 2025-05-21 08:35:39.632 ServerApp] http://127.0.0.1:8888/tree?token=5990de7375c2b246397260a5e97acc68a73c7d20bd1fd67c [I 2025-05-21 08:35:39.632 ServerApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation). [C 2025-05-21 08:35:39.650 ServerApp] To access the server, open this file in a browser: file:///home/picca/.local/share/jupyter/runtime/jpserver-127457-open.html Or copy and paste one of these URLs: http://localhost:8888/tree?token=5990de7375c2b246397260a5e97acc68a73c7d20bd1fd67c http://127.0.0.1:8888/tree?token=5990de7375c2b246397260a5e97acc68a73c7d20bd1fd67c /usr/lib/python3/dist-packages/nbclassic/tree/handlers.py:51: RuntimeWarning: coroutine 'AsyncFileContentsManager.dir_exists' was never awaited if cm.dir_exists(path=path): RuntimeWarning: Enable tracemalloc to get the object allocation traceback /usr/lib/python3/dist-packages/nbclassic/tree/handlers.py:52: RuntimeWarning: coroutine 'AsyncFileContentsManager.is_hidden' was never awaited if cm.is_hidden(path) and not cm.allow_hidden: RuntimeWarning: Enable tracemalloc to get the object allocation traceback [I 2025-05-21 08:35:40.964 NotebookApp] Refusing to serve hidden directory, via 404 Error [W 2025-05-21 08:35:41.029 NotebookApp] 404 GET /tree?token=[secret] ([email protected]) 68.84ms referer=None
