A simple test follows:

Message exists!

WARN [freemarker.template.instruction.VariableInstruction.process]: Couldn't get value of expression me: message is not a TemplateHashModel, it's a freemarker.template.FastScalar
WARN [freemarker.template.instruction.TransformInstruction.process]: Couldn't get referent of sdf: message is not a TemplateHashModel, it's a freemarker.template.FastScalar