Once fixed to get rid of the errors (lacking a semi-colon and a bad variable name), the code you’ve posted does work – I’ve just tried it and it showed the names and values with no problems.
My guess is that in reality, you’re trying to use fields which aren’t public. This code:
FieldInfo fields = data.GetType().GetFields();
… will only get public fields. You would normally need to specify that you also want non-public fields:
FieldInfo fields = data.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
(I hope you don’t really have public fields, after all…)