<p>I'm setting up my Jenkins server, and on simple requests in the web interface, like creating a folder, a pipeline, a job, etc., I periodically get the following error:</p>

<pre><code>HTTP ERROR 403
Problem accessing /job/Mgmt/createItem. Reason:

    No valid crumb was included in the request
</code></pre>

<p>The server is using the Jenkins/Jenkins container, orchestrated by Kubernetes on a cluster on AWS created with kops. It sits behind a class ELB.</p>

<p>Why might I be experiencing this? I thought the crumb was to combat certain CSRF requests, but all I'm doing is using the Jenkins web interface.</p>

<p>Enabling proxy compatibility may help to solve this issue. 
Go to Settings -> Security -> <strong>Enable proxy compatibility</strong> in CSRF Protection section</p>

<blockquote>
  <p>Some HTTP proxies filter out information that the default crumb issuer uses to calculate the nonce value. If an HTTP proxy sits between your browser client and your Jenkins server and you receive a 403 response when submitting a form to Jenkins, checking this option may help. Using this option makes the nonce value easier to forge.</p>
</blockquote>
