You can see this error if the token is from a user that has a valid CircleCI account, but that user either does not have access to the organization or does not have access to modify contexts.
You can check this in the UI by going to the contexts page for that organization
https://app.circleci.com/settings/organization/{gitub or bitbucket}/{organization name}/contexts
Replace {github or bitbucket} with either github or bitbucket and {organization name} with the name of your organization. Example circleci.
If you do not have the required permissions you will see an error on that page. The user needs to be an admin of the organization on Github or Bitbucket.