Weird error happend on one of my screens when I tried to call it, all my other screens worked perfectly.
Removed the two MDS jars from my Model and View projects and like magic errors appeared in my build.
Fixed up the errors (mainly related to refactoring and windows not recognising a difference in upper/ lowercase). Also had to do a clean before I built and remove the project directory in the o.j2ee folder.
NOTE: Refactoring and changing case is dangerous.
Also had this error where I had misspelt a task flow name.