Failure to start Kernel as `traitlets` module used by Jupyter could be outdated

Python kernels can fail to start if the Jupyter server failed to start due to an outdated version of traitlets module.

Recommended solution

• Please consider updating trailets to the latest version 5.1.1 or later.
• More information on this can be found here https://github.com/microsoft/vscode-jupyter/issues/8295
• If that still doesn't help, please review the logs (use the command Jupyter: View Output to identify the probably cause)