.StartEditRow returning an "Object reference not set to an instance of an object." error at a DevExpress ASPxGridView even when .AddNewRow works just fine

At the markup for ASPxGridView something between...

<Templates>
   <EditForm>

 
 

...and...

 
 

   </EditForm>
</Templates>

 
 

...something could be jacked up. For me however, when this happened, the HtmlEditFormCreated event was calling .GetRowValues on the ASPxGridView at a code behind and handing in bad values.