The version 1.3 of Form udpates the Form dialog.
Properties like "contactMailBody" and "confirmMailBody" are removed and are replaced by confirmContentType[text||html].
But this update is never applied to the content.

So if an author created a confirmation email on Form 1.2.4 and then updates to Form 1.3, when he opens the dialog, he wont see anymore the confirmation email message.
Bound to "confirmMailBody" before, the dialog expects that this message comes from "confirmContentType[text||html]" now.

An update of the content is required in the version handler.
We could try to follow the logic described in MGNLFORM-119.

Fortunately, the "sendEmail" processor is still working. It checks for both values... but it's a bit confusing. See MGNLFORM-118.

NOTE FOR STK:
PUR is extending Form and is also impacted. Its dialog extend "Form dialog", so maybe the same logic of content update should be added to the version handler of STK.

NOTE FOR Mgnl 4.5:
The old properties are replaced during the migration process.