An external system is using bulk api to insert records in Salesforce. Salesforce throws an error saying - MISSING_ARGUMENT:fiedXXX__c not specified:-- where XXX is external Id of Parent of the records that is being inserted.

I did some research online and found this article related to this - https://success.salesforce.com/issues_view?id=a1p30000000T4SJAA0

The external system is inserting with parent's external id as #N/A. Is there any solution to this ? The article mention no fix and ask to use Synchronous API - REST API? Is there any other work around for this using Bulk API?

An external system is using bulk api to insert records in Salesforce. Salesforce throws an error saying -

MISSING_ARGUMENT:fiedXXX__c not specified:-- where XXX is external Id of Parent of the records that is being inserted.

I did some research online and found this article related to this - https://success.salesforce.com/issues_view?id=a1p30000000T4SJAA0

The external system is inserting with parent's external id as #N/A. Is there any solution to this ? 

The article mention no fix and ask to use Synchronous API - REST API? Is there any other work around for this using Bulk API?