题意：Jupyter Lab 在显示小部件时遇到问题（JavaScript 错误）

问题背景：

I have troubles replicating a JupyterLab install on a new PC. It is working fine on my previous one. I am unable to display simple widgets (like a checkbox from ipywidgets or ipyvuetify). I checked that jupyter-widgets is enabled with jupyter labextension list. The results is :

我在新电脑上安装 JupyterLab 时遇到了问题，在我之前的电脑上它可以正常工作。我无法显示简单的小部件（如来自 ipywidgets 或 ipyvuetify 的复选框）。我检查了是否已使用 jupyter labextension list 启用了 jupyter-widgets。结果是：

jupyter-vue v1.7.0 enabled ok
jupyter-vuetify v1.8.4 enabled ok
@jupyter-widgets/jupyterlab-manager v5.0.2 enabled ok (python, jupyterlab_widgets)

In the notebook, when i try to display a widget, the cell displays a Javascrip error :

在笔记本中，当我尝试显示一个小部件时，单元格显示了一个 JavaScript 错误：

[Open Browser Console for more detailed log - Double click to close this message]
Failed to load model class 'CheckboxModel' from module '@jupyter-widgets/controls'
Error: Module @jupyter-widgets/controls, version ^1.5.0 is not registered, however, 2.0.0 is 
at f.loadClass (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab-
manager/static/134.083e6b37f2f7b2f04b5e.js?v=083e6b37f2f7b2f04b5e:1:74976)
at f.loadModelClass (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab- 
manager/static/150.467514c324d2bcc23502.js?v=467514c324d2bcc23502:1:10721)
at f._make_model (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab- 
manager/static/150.467514c324d2bcc23502.js?v=467514c324d2bcc23502:1:7517)
at f.new_model (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab- 
manager/static/150.467514c324d2bcc23502.js?v=467514c324d2bcc23502:1:5137)
at f.handle_comm_open (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab- 
manager/static/150.467514c324d2bcc23502.js?v=467514c324d2bcc23502:1:3894)
at _handleCommOpen (http://localhost:8888/lab/extensions/@jupyter-widgets/jupyterlab- 
manager/static/134.083e6b37f2f7b2f04b5e.js?v=083e6b37f2f7b2f04b5e:1:73392)
at b._handleCommOpen (http://localhost:8888/static/lab/jlab_core.86360d749a1ef5f29afb.js? 
v=86360d749a1ef5f29afb:2:924842)
at async b._handleMessage 
(http://localhost:8888/static/lab/jlab_core.86360d749a1ef5f29afb.js? 
v=86360d749a1ef5f29afb:2:926832)

问题解决：

That error is consistent with one noted here in an issue report recently. The suggestion there is to change to ipywidgets version 7.7.2 or 7.6.5 to fix this issue. Also, see the note here, too.

这个错误与最近在一份问题报告中提到的一个错误一致。那里的建议是更改到 ipywidgets 的 7.7.2 或 7.6.5 版本来解决这个问题。另外，也请参考这里的说明。