Drools application throws ClassNotFoundException when using "mvel" as a dialect

Issue

• Drools application sporadically throws the following exception stack when using the "mvel" dialect for rules :

  Exception in thread "main" java.lang.NoClassDefFoundError: some/application/Class
       at ASMAccessorImpl_XXXXXXXXXXXXXXXXXX.getValue(Unknown Source)
       at org.mvel2.optimizers.dynamic.DynamicGetAccessor.getValue(DynamicGetAccessor.java:66)
       at org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:99)
       at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:102)
       at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:102)
       at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:102)
          at org.mvel2.compiler.ExecutableAccessor.getValue(ExecutableAccessor.java:41)...Caused by: java.lang.ClassNotFoundException: some.application.Class
       at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
       at java.security.AccessController.doPrivileged(Native Method)
       at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
       at java.lang.ClassLoader.loadClass(ClassLoader.java:319)
       at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:330)
       at java.lang.ClassLoader.loadClass(ClassLoader.java:254)
          at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:402)