I got the following error
EntityMetadataWrapperException: Unable to get the data property commerce_total as the parent data structure is not set. in EntityStructureWrapper->getPropertyValue() line 442 ...
...on a data export of a view (at a commerce site) with some complex 'relationships' between line items and orders.
I sorted it out by using 'filtering criteria' to filter out rows that had empty results.
Said in another way: The fields generated from the relations was sometimes empty and that gave me errors...
Not sure if this is a views data export, a views, a commerce or an entity related error - or even a "real" error - but I got it after using views_data_export!
My main reason for posting it here is that it might help somebody else with a similar error :)