How to handle Jupyter Notebook NBextension config error?

I installed nbextension to my Jupyter Notebook. But when I was using large datasets it made a big slow down. Then I removed NBExtension but after uninstallation, 500 Internal Server error started. Now I tried to reinstall Anaconda but the problem is still there.

     nbextensions_configurator/config_menu/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/config_menu/main
  contrib_nbextensions_help_item/main enabled
  - Validating: ok
  hinterland/hinterland enabled
  - Validating: ok
  autosavetime/main enabled
  - Validating: ok
  select_keymap/main enabled
  - Validating: ok
  jupyter-js-widgets/extension disabled
tree section
  nbextensions_configurator/tree_tab/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/tree_tab/main
edit section
  ruler/edit enabled
  - Validating: ok
  codefolding/edit enabled
  - Validating: ok
config dir: C:\ProgramData\Anaconda3\etc\jupyter\nbconfig
notebook section
  jupyter-js-widgets/extension enabled
  - Validating: ok
  nbextensions_configurator/config_menu/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/config_menu/main
tree section
  nbextensions_configurator/tree_tab/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/tree_tab/main
config dir: C:\ProgramData\jupyter\nbconfig
notebook section
  nbextensions_configurator/config_menu/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/config_menu/main
tree section
  nbextensions_configurator/tree_tab/main enabled
  - Validating: problems found:
    - require?  X nbextensions_configurator/tree_tab/main