When you test the behaviour of a component with incorrect requests (when you develop a server or, like me, Web Application Firewall rules), the GUI generates an exception when trying to see the response and doesn't display it. Same problem with HTTP4Client and Java. The exception comes from the headers parser. It would be very interesting to have an option to not parse requests and/or responses, thus having only the "Raw" tabs(s). In case other parsers are also used (body?), the same option should apply to them.
This issue has been migrated to GitHub: https://github.com/apache/jmeter/issues/5638