Starting with a brand new installation of Eclipse and making a new WOLips project will immediately give you the following warnings in the lower central pane:
Chuck Hill provided the following solution:
"That is not an error, that is a warning. You can safely ignore it.
To make it go away:
Window - Preferences - Java - Compiler - Errors/Warnings - Potential
Programming Problems and see the top entry."
You'll have to do a rebuild after selecting to ignore "Serializable class without serialVersionUID:"
Voila, no more warnings.