I am using the bundled Tomcat 8.0.5 bundled with TomEE7.0.2(plus). I noticed the version of that was 8.0.5 from the startup logs and downloaded the sources.
I downgraded my Rest Easy from 3.0.4.Final to 2.3.6.Final (which I was using with an older version of TomEE) and the Instance Manager isn't null now. It has a type of org.apache.tomee.catalina.JavaeeInstanceManager now and I got past that error. Still have a warning about this class not being found from a second WAR in my EAR, but that WAR shouldn't even use it since that class is defined and configured only in the first WAR's web.xml and classes directory (as I showed previously). -- Sent from: http://tomee-openejb.979440.n4.nabble.com/TomEE-Dev-f982480.html
