Problem:
Approved Email Administration sync displays the error 'Error: could not upsert Approved Content. The error reported was: (INVALID_FIELD) Foreign key external ID: [EXTERNAL ID] not found for field VExternal_Id_vod__c in entity Product_vod__c.'
Root Cause:
The org is missing a Product_vod__c record that matches the value of the External ID of the Vault Product.
Solution:
Navigate to the product on the document record in question in Vault. Note the value of the External ID field. The error also mentions this value.
In Veeva CRM, navigate to the matching product record (or create one) and record the value of the Vault product's external ID into the VExternal_Id_vod__c field on the product record.
Once updated, navigate back to the Approved Email Administration page and initiate an Incremental Sync.
Related Documentation:
CRM Help Documentation: Integrating CRM and Vault for Approved Email