Error while processing sampler: 'bzm - Parallel Controller'. java.lang.reflect.InaccessibleObjectException: Unable to make field java.lang.ThreadLocal this error facing while using bzm parallel controller in jmeter latest version enter image description here

1 Answer 1


You should review the way you're launching JMeter as it's missing the necessary --add-opens argument for the java.lang package

As of JMeter 5.5 the relevant line looks as follows:

--add-opens java.desktop/sun.awt=ALL-UNNAMED --add-opens java.desktop/sun.swing=ALL-UNNAMED --add-opens java.desktop/javax.swing.text.html=ALL-UNNAMED --add-opens java.desktop/java.awt=ALL-UNNAMED --add-opens java.desktop/java.awt.font=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.base/java.lang.reflect=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.text=ALL-UNNAMED --add-opens=java.desktop/sun.awt.shell=ALL-UNNAMED

So the options are in:

  1. Either add the above line to your java executable arguments
  2. Or launch JMeter using jmeter.bat file provided
  3. Or downgrade your Java to version 8, it is sufficient to run JMeter 5.5 and you won't have to worry about explicitly enabling these modules

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