Workbench - Bulk CSV export - Error: InvalidJob: Unable to find object: childaccounts

I'm getting an error when trying to run SOQL in workbench. The below query works fine if i choose the view as option "list", however if i choose "Bulk CSV" it throws an error? Any thoughts on how to export this without getting that error would be great :)

SELECT id, name, state__c, custid__c, (select state__c FROM childaccounts)

FROM account where owner.name = 'FAKE PERSON' and parentid = '' and solomon_address_key__c = ''