net.sf.jasperreports.engine.JRException: ...
Caused by: net.sf.jasperreports.engine.fill.JRExpressionEvalException:
  Error evaluating expression for source text:
    $P{REPORT_SCRIPTLET}.setTestRaw_LogOn_TstMsgOn(true, true)
Caused by: java.lang.LinkageError: loader constraint violation: loader
  (instance of java/net/FactoryURLClassLoader) previously initiated loading
  for a different type with name "org/slf4j/Logger"