title: Jenkins - No valid crumb was included in request
body: <p>Jenkins - <code>2.263.1(LTS)</code> deployed through <code>tomcat</code> on <code>CentOS-8.2</code>and have <code>Nginx reverse proxy</code> running in-front of Jenkins.</p>
  <p>Under <code>Manage Jenkins</code> &gt; <code>Configure Systems</code> - <code>Apply</code> and <code>Save</code> not working, Due to this error, i cannot <code>Apply</code> (or) <code>Save</code> any of my configurations, It always shows below error on browser (Firefox &amp; Chrome).</p>
  <blockquote>
  <p>HTTP Status 403 – Forbidden</p>
  <p>Type Status Report</p>
  <p>Message No valid crumb was included in the request</p>
  <p>Description The server understood the request but refuses to authorize
  it. Apache Tomcat/9.0.30</p>
  </blockquote>
  <p>Also <code>Jenkins</code> &gt; <code>Manage Jenkins</code> &gt; <code>Configure Global Security</code> - <code>Apply</code> works. But <code>Save</code> not working this too results same above given error.</p>
  <p><code>Systems log</code> error message.</p>
  <blockquote>
  <p>Feb 19, 2021 10:56:05 AM WARNING hudson.security.csrf.CrumbFilter
  doFilter No valid crumb was included in request for
  /jenkins/configSubmit by ankit.sahu. Returning 403.</p>
  </blockquote>
  <p><strong>Workaround tried:-</strong></p>
  <pre><code>1) Under Configure Global security &gt; CSRF Protection &gt; Enable proxy compatibility( Tick marked Enabled). - Didn't work so disabled with below command.
  2) hudson.security.csrf.GlobalCrumbIssuerConfiguration.DISABLE_CSRF_PROTECTION = true - Even this didn't solve the problem.
  3) Installed the Strict Crumb Issuer plugin.
     Enabled this plugin and unchecked Check the session ID from its configuration (Under Jenkins Configure Global Security).
  4) Restated the Jenkins.
  </code></pre>
  <p>Even tried by adding below in <code>/apache-tomcat-9.0.30/conf/tomcat-users.xml</code> file.</p>
  <pre><code>&lt;?xml version='1.0' encoding='utf-8'?&gt;
  &lt;tomcat-users&gt;
      &lt;role rolename=&quot;manager-gui&quot;/&gt;
      &lt;role rolename=&quot;manager-script&quot;/&gt;
      &lt;role rolename=&quot;manager-jmx&quot;/&gt;
      &lt;role rolename=&quot;manager-status&quot;/&gt;
      &lt;role rolename=&quot;admin-gui&quot;/&gt;
      &lt;role rolename=&quot;admin-script&quot;/&gt;
      &lt;user username=&quot;user&quot; password=&quot;password&quot; roles=&quot;manager-gui,manager-script,manager-jmx,manager-status,admin-gui,admin-script&quot;/&gt;
  &lt;/tomcat-users&gt; 
  </code></pre>
  <p>However still experiencing same problem. I don't know how to fix it, Can someone help me?</p>