The scenario is:

• Grid popup editing
• The model class has no parameterless constructor
• The Grid is using a popup <FormTemplate>

In this case, the Grid should not try to create or clone an edit item on its own. Instead, it should rely on the returned instance from OnModelInit. However, the Grid first fires OnModelInit and then it still tries to clone or create an edit item, which causes an exception.

A possible workaround is to manage the whole edit process manually, similar to the example with ListView popup editing.