I've finally solved the problem.
I had renamed the DefaultDS in the mysql-ds.xml file. Ignorant to the Fact that by default JBOSS uses that DS and is referenced everywhere! So if you want to rename that then you have to make the changes on MANY places (see file login-config.xml and all the files inside the Deploy folder). There is a document from Adobe where it explains how to upgrade from LiveCycle 7.x to ES and it explicitly says that there most be a DS with the name of "DefaultDS". If they mention this anywhere else, I've never seen it though.
Anyways now I modified the mysql-ds.xml to include the original DefaultDS jndi and added my owns too. So my file looks more like this:
MySqlDS
jdbc:mysql://localhost:3306/myownDb
com.mysql.jdbc.Driver
myUser
myPwd
org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter
mySQL
DefaultDS
jdbc:mysql://localhost:3306/adobe
com.mysql.jdbc.Driver
adobe
pwd
org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter
mySQL
I hope this help anyone out there with the same error.