The "identifier" is the combined name of a field and the nodes that it was pulled through that you used in your export definition. You will need to edit the names of the nodes used for some of the fields in the export definition to shorten the "identifier".
  1. In Administration click Export Definitions
  2. Click the drop-down and Edit the export definition used in your export
  3. In the Selected Fields section, find the fields that is listed in the error message. For example, if the identifier in the error message is MembershipsMembershipTransaction1RevApplRevDetailsSalesOrderSalesOrderItemSalesOrderItemMemshpSalesOrderItemMemshpItemPromotionM, then find and click on the selected field Promotion under Memberships, Membership Transaction, Revenue Application Details, Revenue Details, Sales Order, Sales Order Item, Sales Order Item Membership.
  4. Click to highlight the nodes in that section and click the pencil icon to "Change Column Header"
  5. Give each of the nodes a shortened name or abbreviation to help lessen the length
  6. Save and close
  7. Back in Administration click Export
  8. Click the drop-down next to the export process and click Start Export