String body = inMessage.getBody(String.class);
Yes. I did a:
String inString = inMessage.getBody(String.class);
The issue is inString == null.
And after some investigation it's the same issue 8624 The only difference is the ftp component throws a org.apache.camel.NoTypeConversionAvailableException. And this time I didn't get an exception. Just a null returned?
Make sure all the type converters can be loaded when you startup Camel.
And if you do a mandatory body
String inString = inMessage.getMandatoryBody(String.class);
It will throw an exception if the body is null or cannot be converted.