In case you try to load the CRAM-system and want to access bullet-based reasoning, you might stumble across this error. To make CL-BULLET work correctly, the JSON-PROLOG-node has to run correctly. This can be done by directly starting the node or via launch files:

<launch>
  <node name="json_prolog" pkg="json_prolog" type="json_prolog">
    <param name="initial_package" value="your-package-name" />
  </node>
</launch>

To make sure that JSON-PROLOG is able to run, you have to set your JAVA_HOME environment variable. Add this to your `~/.bashrc' (assuming that this is the path to your Java JDK):

export JAVA_HOME=/usr/lib/jvm/java-6-openjdk/

Restart your shell afterwards to let changes take effect.