This post explains my problem best,
http://stackoverflow.com/questions/27992636/spring-servlets-and-async-support-in-grails-2-4-4I
have had this error for a long time.. When in dev machine, I am not
behind an apache proxy so my websocket connection works fine, but on
the production machine the websocket fails so the fallbacks
(xhr_streaming, xhr, etc) are used and thats when I get this error.
I have checked the servlet version in BuildConfig, and my tomcat.scan is set to true...
I will jump for joy and be head over hills if someone can point me in the right direction of a fix.
Thanks