I am building a custom processor that publishes a message to an internal system. I am getting an error that the "transfer relationship is not specified", and I haven't been able to figure out why. As far as I can see I am following what I have seen online and in other processors. Here is the code: public void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException { FlowFile flowFile = session.get(); if ( flowFile == null ) { return; } final AtomicReference<String> contentsRef = new AtomicReference<>(null); session.read(flowFile, (inputStream) -> { final String content = IOUtils.toString(inputStream, StandardCharsets.UTF_8); contentsRef.set(content); }); try { final ValidatedEventStoreProducer producer = initializeProducer(context, session, flowFile); producer.publishEvent(contentsRef.get(), Topics.IQ_EVENT_GENERAL, TenantId.fromValidated(flowFile.getAttribute("tenantid"))); } catch (Exception exception) { session.transfer(flowFile, REL_FAILURE); return; } session.transfer(flowFile, REL_SUCCESS); } None of the operations return an updated flowFile so it is the right one I am sending. To test that I tried the following code: public void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException { FlowFile flowFile = session.get(); if ( flowFile == null ) { return; } session.transfer(flowFile, REL_SUCCESS); } and even: public void onTrigger(final ProcessContext context, final ProcessSession session) throws ProcessException { FlowFile flowFile = session.get(); if ( flowFile == null ) { return; } session.remove(flowFile); } I still get " transfer relationship not specified". I have my relationship set up like this: public static final Relationship REL_SUCCESS = new Relationship.Builder() .name("success") .description("Files that are successfully send will be transferred to success") .build(); public static final Relationship REL_FAILURE = new Relationship.Builder() .name("failure") .description("Files that fail to send will transferred to failure") .build(); These are added to the relationships Set.   If anyone could give me some advice and/or let me know where I'm going wrong I would really appreciate that! Thanks! ... View more