Could not authenticate reader : @ionic/cli-plugin-ionic1

Hi,
When I do my npm serve, I got this error:

{
   "error": {
   "code": "E401",
   "summary": "Could not authenticate reader : @ionic/cli-plugin-ionic1",
   "detail": ""
  }
}

How can this be solved?

Thanks!

What is this?

The error message seems to be pretty unique, internet-wide…

This is the documentation for npm serve
https://www.npmjs.com/package/serve

Yes I looked on internet and this error is nowhere to be found…

And what are you using this for?

The string “reader” doesn’t appear in the repo of https://github.com/zeit/serve, which is the code behind npm serve. Do you have an idea where the error message might come from? Where exactly do you get the error? Can you post the whole output with the command that causes it?