I would enable
com.arjunaTRACE logging that shows the JTA transaction starting/ending. Also, I would enable
org.jboss.as.jpa (JPA) logging that shows what is going on at the JPA container level. To do this, follow the instructions here. The output will be in the WildFly application server console and also in the server.log file as well.
Thank you for your response. Very helpful.
I actually started with a new environment.
I downloaded Eclipse Neon - Oracle Enterprise Pack for Eclipse (184.108.40.206.1)
Then installed Jboss tools from the marketplace which included the Wildfly 10.0.0 experimental server.
Then added a user library to include Eclipselink 2.6.2
This has got my app working again, i.e. it has solved the issue of not persisting.
I'm curious to know if all of the above is possible to use with the Jboss developer studio?
I downloaded 9.1.0 beta 2 and attempted to use it... but its JPA configuration is completely locked out (greyed out).
I would also be interested to know what development tools are preferred by developers working with Wildfly?
I'm not really sure why the JPA configuration is greyed out for you in JBoss developer studio. I don't have any answers about which development tools are preferred by developers. I know that some like http://tools.jboss.org and some like intellij. I believe that both environments should work for you. There is a developer studio user forum linked from here, perhaps you could ask how to unlock the JPA configuration menu there.