title: How can I fix java.lang.NullPointerException caused by TraceGovernor in Jaspersoft studio plugin?
body: <p>I'm writing plugin for Jaspersoft studio up-to-date. The plugin crashes, when it is trying to open preview of report. (from the plugin) Stack Trace of java.lang.NullPoinpointerException:</p>
  
  <pre><code>com.jaspersoft.studio.debug.TraceGovernor.setup(TraceGovernor.java:111)
  com.jaspersoft.studio.debug.TraceGovernor.initMaps(TraceGovernor.java:118)
  com.jaspersoft.studio.debug.TraceGovernor.beforeReportInit(TraceGovernor.java:162)
  net.sf.jasperreports.engine.fill.JRFillDatasetScriptlet.beforeReportInit(JRFillDatasetScriptlet.java:74)
  net.sf.jasperreports.engine.JRAbstractScriptlet.callBeforeReportInit(JRAbstractScriptlet.java:176)
  net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:236)
  net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:115)
  net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:580)
  net.sf.jasperreports.engine.fill.BaseReportFiller.fill(BaseReportFiller.java:414)
  net.sf.jasperreports.engine.fill.BaseFillHandle$ReportFill.run(BaseFillHandle.java:119)
  java.lang.Thread.run(Thread.java:745)
  </code></pre>
  
  <p>Non of code in stack trace is mine. I think it can't load necessary classes. (Jaspersoft studio can load all necessary libraries) Does anyone know, what to do with it please? Many thanks.</p>
  
  <hr>
  
  <h2>Edit</h2>
  
  <p>I've found, that it's caused by this property in Jaspersoft studio, that loads extension, that is loading <code>TraceGovernor</code>. It's for debugging report, but it isn't compatible with my plug-in.</p>
  
  <pre><code>net.sf.jasperreports.extension.registry.factory.governor=com.jaspersoft.studio.debug.TraceGovernorExtensionsRegistryFactory
  </code></pre>
  
  <p>I've solved that by removing it from java package <code>com.jaspersoft.studio_6.3.0.final.jar\jasperreports_extension.properties</code>, but I would like some non-destructive method, how to disable this extension. </p>