title: Puppeteer Error: Chromium revision is not downloaded
body: <p>I used <code>npm i puppeteer</code> as stated in the <a href="https://github.com/GoogleChrome/puppeteer#getting-started" rel="noreferrer">Documentation</a>
  and I'm getting the following error:</p>
  
  <p><strong>(node:2066) UnhandledPromiseRejectionWarning: Error: Chromium revision is not downloaded. Run "npm install" or "yarn install"
      at Launcher.launch</strong> </p>
  
  <p>when im trying this example (also from the docs):</p>
  
  <pre><code>const puppeteer = require('puppeteer');
  (async () =&gt; {
    const browser = await puppeteer.launch();
    const page = await browser.newPage();
    await page.goto('https://example.com');
    await page.screenshot({path: 'example.png'});
    await browser.close();
  })();
  </code></pre>
  
  <p>Also in the documentation:</p>
  
  <blockquote>
    <p>Note: When you install Puppeteer, it downloads a recent version of Chromium (~170MB Mac, ~282MB Linux, ~280MB Win) that is guaranteed to work with the API.</p>
  </blockquote>
  
  <p>Any help would be appreciated.</p>