Cannot use build-in functions

java.lang.RuntimeException: Failed to load custom mapping
	at org.apache.camel.component.dozer.CustomMapper.mapCustom(CustomMapper.java:80)
	at org.apache.camel.component.dozer.CustomMapper.convert(CustomMapper.java:41)
	at org.dozer.MappingProcessor.mapUsingCustomConverterInstance(MappingProcessor.java:977)
	at org.dozer.MappingProcessor.mapFromFieldMap(MappingProcessor.java:355)
	at org.dozer.MappingProcessor.mapField(MappingProcessor.java:307)
	at org.dozer.MappingProcessor.map(MappingProcessor.java:267)
	at org.dozer.MappingProcessor.mapToDestObject(MappingProcessor.java:216)
	at org.dozer.MappingProcessor.createByCreationDirectiveAndMap(MappingProcessor.java:196)
	at org.dozer.MappingProcessor.mapGeneral(MappingProcessor.java:170)
	at org.dozer.MappingProcessor.map(MappingProcessor.java:104)
	at org.dozer.MappingProcessor.map(MappingProcessor.java:99)
	at org.dozer.DozerBeanMapper.map(DozerBeanMapper.java:120)
	at org.apache.camel.component.dozer.DozerProducer.process(DozerProducer.java:79)
	at org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process(AsyncProcessorConverterHelper.java:61)
	at org.apache.camel.processor.SendProcessor.process(SendProcessor.java:129)
	at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
	at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:448)
	at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:191)
	at org.apache.camel.processor.Pipeline.process(Pipeline.java:118)
	at org.apache.camel.processor.Pipeline.process(Pipeline.java:80)
	at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:191)
	at org.apache.camel.component.file.GenericFileConsumer.processExchange(GenericFileConsumer.java:433)
	at org.apache.camel.component.file.GenericFileConsumer.processBatch(GenericFileConsumer.java:211)
	at org.apache.camel.component.file.GenericFileConsumer.poll(GenericFileConsumer.java:175)
	at org.apache.camel.impl.ScheduledPollConsumer.doRun(ScheduledPollConsumer.java:174)
	at org.apache.camel.impl.ScheduledPollConsumer.run(ScheduledPollConsumer.java:101)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
	at org.apache.camel.component.dozer.CustomMapper.mapCustom(CustomMapper.java:72)
	... 32 more