title: Jmeter - java.lang.NullPointerException when running a few users
body: <p>I've been working on jmeter stress tests, and found an issue that i'm not able to solve.</p>
  
  <p>So if I run a testplan with an user all works peachy, I'm able to scale it until 25 simultaneous users.</p>
  
  <p>As soon as I try to use 26 user using any ramp up I get the following error.</p>
  
  <pre><code>2014/01/06 11:17:19 ERROR - jmeter.threads.JMeterThread: Exception processing Assertion  java.lang.NullPointerException
      at org.apache.jmeter.assertions.ResponseAssertion.evaluateResponse(ResponseAssertion.java:329)
      at org.apache.jmeter.assertions.ResponseAssertion.getResult(ResponseAssertion.java:201)
      at org.apache.jmeter.threads.JMeterThread.processAssertion(JMeterThread.java:706)
      at org.apache.jmeter.threads.JMeterThread.checkAssertions(JMeterThread.java:677)
      at org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:439)
      at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:256)
      at java.lang.Thread.run(Thread.java:722)
  </code></pre>
  
  <p>Thanks in advance</p>