Can't access favicon from Production (Manifest: Line: 1, column: 1, Syntax error.)

I can't access the favicon when I deploy to Production for my website http://thymelessapp.com/thymelessfavicon.ico even though it works in my local version.

I'm seeing the following error in the console, which I'm assuming is related:

Manifest: Line: 1, column: 1, Syntax error.

I also can't access any other assets in the public folder of my react app. We're using gcloud in our Production server.

This is our manifest file:

{
  "short_name": "Thymeless",
  "name": "Thymeless",
  "icons": [
    {
      "src": "thymelessfavicon.ico",
      "sizes": "64x64 32x32 24x24 16x16",
      "type": "image/x-icon"
    },
    {
      "src": "logo192.png",
      "type": "image/png",
      "sizes": "192x192"
    },
    {
      "src": "logo512.png",
      "type": "image/png",
      "sizes": "512x512"
    }
  ],
  "start_url": ".",
  "display": "standalone",
  "theme_color": "#000000",
  "background_color": "#ffffff"
}

Here is my index.html file:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />

    <link rel="icon" href="../src/images/thymelessfavicon.ico" />

    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <meta name="theme-color" content="#000000" />
    <meta
      name="description"
      content="Thymeless helps you order freshly-made meals for your week from meal-prep services near you
"
    />
    <link rel="apple-touch-icon" href="%PUBLIC_URL%/logo192.png" />
    <!--
      manifest.json provides metadata used when your web app is installed on a
      user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
    -->
    <link rel="manifest" crossorigin="use-credentials"  href="%PUBLIC_URL%/manifest.json" />
    <!--
      Notice the use of %PUBLIC_URL% in the tags above.
      It will be replaced with the URL of the `public` folder during the build.
      Only files inside the `public` folder can be referenced from the HTML.

      Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
      work correctly both with client-side routing and a non-root public URL.
      Learn how to configure a non-root public URL by running `npm run build`.
    -->
    <title>Thymeless</title>
  </head>
  <body>
    <noscript>You need to enable JavaScript to run this app.</noscript>
    <div id="root"></div>
    <!--
      This HTML file is a template.
      If you open it directly in the browser, you will see an empty page.

      You can add webfonts, meta tags, or analytics to this file.
      The build step will place the bundled scripts into the <body> tag.

      To begin the development, run `npm start` or `yarn start`.
      To create a production bundle, use `npm run build` or `yarn build`.
    -->
  </body>
</html>

Solution

Turns out I had to modify my app.yaml file for gcloud to upload the favicon:

runtime: python27
threadsafe: true

service: default

handlers:
- url: /static
  static_dir: build/static

- url: /favicon\.ico
  static_files: build/favicon.ico
  upload: build/favicon\.ico

- url: .*
  static_files: build/index.html
  upload: build/index.html
  secure: always
  redirect_http_response_code: 301

It now works!