Windows の Jupyter kernel 起動せず

既存のユーザなら

jupyter console --kernel=python3

でも，また jupyter notebook でも起動するが，今年度の新規学生だと，以下のようになって起動しない。

> jupyter console --kernel=python3
Traceback (most recent call last):
File "c:\python38\lib\ntpath.py", line 647, in realpath
path = _getfinalpathname(path)
OSError: [WinError 59] 予期しないネットワーク エラーが発生しました。: '\\\\chaos-2\\home\\25\\h21z0001\\windows\\_redirected\\AppData\\Roaming\\jupyter\\runtime\\kernel-8040.json'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "c:\python38\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "c:\python38\lib\runpy.py", line 87, in _run_code
exec(code, run_globals)
File "C:\Python38\Scripts\jupyter-console.EXE\__main__.py", line 7, in <module>
File "c:\python38\lib\site-packages\jupyter_core\application.py", line 254, in launch_instance
return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
File "c:\python38\lib\site-packages\traitlets\config\application.py", line 844, in launch_instance
app.initialize(argv)
File "c:\python38\lib\site-packages\traitlets\config\application.py", line 87, in inner
return method(app, *args, **kwargs)
File "c:\python38\lib\site-packages\jupyter_console\app.py", line 137, in initialize
self.init_shell()
File "c:\python38\lib\site-packages\jupyter_console\app.py", line 104, in init_shell
JupyterConsoleApp.initialize(self)
File "c:\python38\lib\site-packages\jupyter_client\consoleapp.py", line 341, in initialize
self.init_kernel_manager()
File "c:\python38\lib\site-packages\jupyter_client\consoleapp.py", line 293, in init_kernel_manager
self.kernel_manager.start_kernel(**kwargs)
File "c:\python38\lib\site-packages\jupyter_client\manager.py", line 309, in start_kernel
kernel_cmd, kw = self.pre_start_kernel(**kw)
File "c:\python38\lib\site-packages\jupyter_client\manager.py", line 264, in pre_start_kernel
kernel_cmd = self.format_kernel_cmd(extra_arguments=extra_arguments)
File "c:\python38\lib\site-packages\jupyter_client\manager.py", line 201, in format_kernel_cmd
ns = dict(connection_file=os.path.realpath(self.connection_file),
File "c:\python38\lib\ntpath.py", line 651, in realpath
path = _getfinalpathname_nonstrict(path)
File "c:\python38\lib\ntpath.py", line 601, in _getfinalpathname_nonstrict
path = _getfinalpathname(path)
OSError: [WinError 59] 予期しないネットワーク エラーが発生しました。: '\\\\chaos-2\\home\\25\\h21z0001\\windows\\_redirected\\AppData\\Roaming\\jupyter\\runtime\\kernel-8040.json'

また，新規学生が jupyter notebook で Web ブラウザを使おうとしても，console でエラーなので，ブラウザでも以下のように Kernel error となって使えない。