title: Google Apps Script returns Sorry, unable to open the file at this time. Please check the address and try again
body: <p>I am trying to <code>POST</code> a request to a simple app script. 
  Here's the code:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var BACKEND_URL = "https://script.google.com/macros/s/AKfycbyYAWMv6O8Xld1EvqPuBk9EgxgfpVNly3dyX3JkSc3h/dev";
  data = {"obj1": "data1", "obj2": "data2"};
  function doGet() {
    var resp = UrlFetchApp.fetch(BACKEND_URL, {
      'method': 'post',
      'contentType': 'application/json',
      'payload': JSON.stringify(data),
      'muteHttpExceptions': true
    });
    Logger.log(resp);
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>And here's the code for the server which should accept POST requests:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>function doGet() {
  }
  
  function doPost(e) {
    Logger.log("posted");
    return;
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>NOTE: there's no user part in the URL, so this question isn't the same as a similar one posted in SO.</p>
  
  <p>As a response a get an html page where it's said that sorry, Sorry, unable to open the file at this time. Please check the address and try again.</p>
  
  <p>I've re-checked the page and it does exist.</p>