Adding a field to old versions of a form

Question

In infopath I added some fields to upgrade an existing from.

The problem is that when old saved forms are opened, all the new fields are greyed out and unusuable. I just want to take their default values and be usable.

How can you achieve this?

Answer 1

The answer is that you need existing forms to increment their version number in their XML headers. The XML xsn forms keep track of which versions had which fields, so new fields are disabled on older forms.