InfoPath Dev

We have several hundred forms that exist. We want to add another field/control. Everything adds ok, however when you open any one of the existing forms, the newly added control is greyed out.

How can we activate this new field on existing forms?

I believe I have seen that before. I think it is because the old xml files you have do not have the new field in the xml itself. For instance,

The old form xml was:
<Foo><Bar></Bar></Foo>

And the new one now has:
<Foo><Bar></Bar><NewField></NewField></Foo>

You need to add <NewField></NewField> to your old xml. That may be the issue. I do not know a good solution off hand but I know someone here may have a good suggestion.

Hello ek38,
To activate the new field in existing old forms please follow the following steps:
1. Open InfoPath form in design mode.
2. Go to Tools -> Form Options -> In Advanced tab.
3. Navigate to Form template version section and select “Automatically upgrade existing forms” in On version upgrade drop down.
4. Click on “OK” and save the changes done.

Hope this helps!