下载插件失败后，打开总报错，每个都是，卸载再安装还会，这是lab的报错
Traceback (most recent call last):
File "D:\computer\python\anaconda3\lib\site-packages\jupyterlab_server\server.py", line 20, in
from notebook.notebookapp import aliases, flags, NotebookApp as ServerApp
File "D:\computer\python\anaconda3\lib\site-packages\notebook\notebookapp.py", line 83, in
from .services.contents.manager import ContentsManager
File "D:\computer\python\anaconda3\lib\site-packages\notebook\services\contents\manager.py", line 17, in
from nbformat import sign, validate as validate_nb, ValidationError
File "C:\Users\17703\AppData\Roaming\Python\Python37\site-packages\nbformat\sign.py", line 26, in
from traitlets import Any, Bool, Bytes, Callable, Enum, Instance, Integer, Unicode, default, observe
ImportError: cannot import name 'Callable' from 'traitlets' (D:\computer\python\anaconda3\lib\site-packages\traitlets_init_.py)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "D:\computer\python\anaconda3\Scripts\jupyter-lab-script.py", line 5, in
from jupyterlab.labapp import main
File "D:\computer\python\anaconda3\lib\site-packages\jupyterlab\labapp.py", line 14, in
from jupyterlab_server import slugify, WORKSPACE_EXTENSION
File "D:\computer\python\anaconda3\lib\site-packages\jupyterlab_server_init_.py", line 4, in
from .app import LabServerApp
File "D:\computer\python\anaconda3\lib\site-packages\jupyterlab_server\app.py", line 9, in
from .server import ServerApp
File "D:\computer\python\anaconda3\lib\site-packages\jupyterlab_server\server.py", line 26, in
from jupyter_server.base.handlers import ( # noqa
ModuleNotFoundError: No module named 'jupyter_server'