Errors and Problems in notebook after nbextensions installation

[kaburelabs]

Hi fellows,

Some days ago, I tried to install an "auto-completer" from nbextensions_configurator in my notebook and after the installation, my notebook and anaconda were completely broke.

I lost all my custom environments and after trying almost all solutions I decided to open this issue.

I tried to uninstall and reinstall both Anaconda and Jupyter but the problem continues.

How can I fix this problem?

The error that shows in prompt when I run the jupyter-notebook is:

[I 18:04:05.736 NotebookApp] [jupyter_nbextensions_configurator] enabled 0.4.1
[I 18:04:05.754 NotebookApp] JupyterLab extension loaded from /home/leonardo/anaconda3/lib/python3.7/site-packages/jupyterlab
[I 18:04:05.754 NotebookApp] JupyterLab application directory is /home/leonardo/anaconda3/share/jupyter/lab
[W 18:04:05.755 NotebookApp] Error loading server extension nbextensions
    Traceback (most recent call last):
      File "/home/leonardo/anaconda3/lib/python3.7/site-packages/notebook/notebookapp.py", line 1615, in init_server_extensions
        mod = importlib.import_module(modulename)
      File "/home/leonardo/anaconda3/lib/python3.7/importlib/__init__.py", line 127, in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
      File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
      File "<frozen importlib._bootstrap>", line 983, in _find_and_load
      File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked
    ModuleNotFoundError: No module named 'nbextensions'
[I 18:04:05.755 NotebookApp] Serving notebooks from local directory: /home/leonardo
[I 18:04:05.755 NotebookApp] The Jupyter Notebook is running at:
[I 18:04:05.755 NotebookApp] http://localhost:8888/?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712
[I 18:04:05.755 NotebookApp]  or http://127.0.0.1:8888/?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712
[I 18:04:05.755 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 18:04:05.771 NotebookApp] 
    
    To access the notebook, open this file in a browser:
        file:///home/leonardo/.local/share/jupyter/runtime/nbserver-11387-open.html
    Or copy and paste one of these URLs:
        http://localhost:8888/?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712
     or http://127.0.0.1:8888/?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712
[E 18:04:07.090 NotebookApp] Could not open static file ''
[W 18:04:07.119 NotebookApp] 404 GET /static/components/react/react-dom.production.min.js (127.0.0.1) 5.11ms referer=http://localhost:8888/tree?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712
[W 18:04:07.389 NotebookApp] 404 GET /static/components/react/react-dom.production.min.js (127.0.0.1) 0.85ms referer=http://localhost:8888/tree?token=b949e4ac9f1ecb3efab1f9174569abac710ce1fd3c71a712