Sometime InfoPath form library doesn’t allow to save the changes made to list item.
It throws following error:-
ExceptionType: ‘SPException’ ExceptionMessage: ‘Changes could not be saved into the
document. The property to change is read-only for the document’s content type, or the
document is missing XML elements or attributes where the changes would be saved.
Try editing the document in a Windows SharePoint Services-compatible XML editor
such as Microsoft Office InfoPath.
This problem happens when the Form Library contains several property promoted fields
and the form for which changes were made and supposed to save , doesn’t contains those
fields and blows up when trying to save.
To fix this issue, double check content type definition and linked field associated with that.
Some time problematic field got created, doesn’t remove just by deactivating/Uninstall of
feature because instance got created.
This is important to find the instance and remove it then use feature to install/activate to work properly.
Action Item to resolve this issue:-
To fix the problematic filed which blows up,
1. Create a unit test to identify the fields used in Infopath Form
2. Now Remove the filed column mapping from the content type associated in a list
3. Similarly remove the field mapping from content type in Site Collection
4. Remove the content type from the Site Collection
5. Redeploy the content Type so that the Push Down mechanism will update the child
And this solved the problem.