Okay, I found one of them. I had declared classes with actual arrays in them. When I change
foo[] SomeField;
into
ArrayList<foo> SomeField;
the first error goes away. I suppose it would be nice if the serializer was
willing to store json arrays into java arrays, but I can live with
ArrayLists. And, of course, it would be good to have a better error message
for that case :).
