title: AWS S3 - key is not expected for the get method
body: <p>Very weird occurrence of this error (see below). Points of note:</p>
  
  <ul>
  <li>Web app in question has >500 daily users, all of them uploading objects into S3 daily</li>
  <li>Two users, have this one error when they try and upload a file</li>
  <li>The same users, if they try a different computer, do not get this error</li>
  <li>Web app is using the EvaporateJS library - <a href="https://github.com/TTLabs/EvaporateJS" rel="nofollow noreferrer">https://github.com/TTLabs/EvaporateJS</a></li>
  <li>There seems to be no pattern with regards to file size (even a tiny &lt;10kb file will cause it)</li>
  <li>The authentication/authorisation component of the web app is handled by the web-app. I.e. - The IAM user associated with generating the S3 upload Url is shared for all web app users, so I have ruled out a permission issue for the IAM user ID in question</li>
  </ul>
  
  <p>Error message:</p>
  
  <pre><code>&lt;Error&gt;
    &lt;Code&gt;InvalidRequest&lt;/Code&gt;
    &lt;Message&gt;
      Key is not expected for the GET method ?uploads subresource
    &lt;/Message&gt;
    &lt;RequestId&gt;
      *****
    &lt;/RequestId&gt;
    &lt;HostId&gt;
      *****
    &lt;/HostId&gt;
  &lt;/Error&gt;
  </code></pre>
  
  <p>From all the points above, the only variable here seems to be the computers. Am I right? Have I overlooked something? If it is the computers, any idea what would be the issue there? An overactive firewall/something else preventing the upload network requests?</p>
  
  <p>Thanks in advance for any guidance in decipher this error message (what does it even mean?!)</p>