puppeteer-firefox: ERROR: failed to call method 'Browser.deleteCookies'

I receive the following error when I try to run the following example using puppeteer-firefox version 0.5.0:

const pptrFirefox = require('puppeteer-firefox');
(async () => {
  const browser = await pptrFirefox.launch({headless: false});
  const page = await browser.newPage();
  await page.goto('https://www.google.com');
  await page.setCookie({name: 'mycookie', value: 'myvalue'});
})();

$ node sample.js 
(node:92226) UnhandledPromiseRejectionWarning: Error: Protocol error (Browser.deleteCookies): ERROR: failed to call method 'Browser.deleteCookies' with parameters {
  "browserContextId": null,
  "cookies": [
    {
      "url": "https://www.google.com/",
      "name": "mycookie"
    }
  ]
}
Expected "<root>.browserContextId" to be |string|; found |object| `null` instead. _dispatch@chrome://juggler/content/protocol/Dispatcher.js:100:15

    at node_modules/puppeteer-firefox/lib/Connection.js:74:56
    at new Promise (<anonymous>)
    at Connection.send (node_modules/puppeteer-firefox/lib/Connection.js:73:12)
    at Page.deleteCookie (node_modules/puppeteer-firefox/lib/Page.js:115:22)
    at Page.<anonymous> (node_modules/puppeteer-firefox/lib/helper.js:32:23)
    at Page.setCookie (node_modules/puppeteer-firefox/lib/Page.js:135:16)
    at Page.<anonymous> (node_modules/puppeteer-firefox/lib/helper.js:32:23)
    at sample.js:6:14

[mjzffr]

I’m closing this issue since the experimental puppeteer-firefox package is no longer maintained. A replacement will be available later this year. You can learn more about Mozilla’s work on this at https://wiki.mozilla.org/Remote

See also https://github.com/puppeteer/puppeteer/pull/5137

[james-berry]

still getting ERROR: failed to call method ‘Browser.getCookies’ using:

const browser = await puppeteer.launch({
    headless: false,
    args: ['--start-fullscreen', '--incognito'],
    devtools: true,
  });