Duplicate Lookup Reference Failure When Import Data File in Dynamics 365

 Sometimes, when we tried to import excel data into Dynamics 365, we may get errors like "A duplicate lookup reference was found.".

For example, I tried to import the invoice list into Dynamics 365 CRM but got two duplicate errors for the Order and Opportunity fields(columns). 

    So, I search the order name on Dynamics 365 CRM,  yes, there are several order records that have the same name as the imported data. 

    Since these orders with the same name have been in Completed status, I can not easily change their name anymore. 

   But thank god, we have a column for Order ID in the spreadsheet. This order ID is unique.

So I determined to import "Order ID" and ignore "Order", and "Opportunity".

Then, map Order ID with Order field (lookup type) on Invoice form of CRM by using Order ID to search Order record.

Finally, I created a workflow to populate the Opportunity field based on Order field when new Invoice record created or Order field changed since there is 1:N relationship between Opportunity and Order Entities.