title: Provided Grok expressions do not match field value in filebeat (audit.log)
body: <p>I have configured audit.log in filebeat to store logs in elasticsearch. But i am getting Provided Grok expressions do not match field value.</p>
  
  <p><strong>and my error.message is:</strong></p>
  
  <p>Error.message: Provided Grok expressions do not match field value: [\tat org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489) [nb-plugin-audit-2.0.jar:na]]</p>
  
  <p><strong>and my message is:</strong></p>
  
  <p>message: at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489) [nb-plugin-audit-2.0.jar:na]</p>
  
  <p>Is there any solution to remove this error?</p>