Just had a two hour bug/problem hunt.
The gwt version (html5) wouldn't run anymore.
The problem was the Json I am using for the game texts. (If I had just used simple string constants...)
<extend-configuration-property name="gdx.reflect.include" value="net.jppresents.space.TextResources" /> <extend-configuration-property name="gdx.reflect.include" value="com.badlogic.gdx.utils.Queue" /
This had to go into the SpaceMain.gwt.xml.
The first one for my json class (this class is filled via reflection when loading the json file). The second one.. no clue why, but ArrayLists can't be deserialized otherwise.
Wow, man I am happy it's up and running again.