refresh attempt failing due to duplicate value

[darb]

Hi PBI refresh attempt is failing due to duplicate value, however I have checked the source (ERP) table and there is not a duplicate record , any ideas on what could be the issue?  below is the error message.   This happen a a week ago and then mysteriously resolved itself 

Failure details: The last refresh attempt failed because of an internal service error. This is usually a transient issue. If you try again later and still see this message, contact support.

Column '<ccon>SKU</ccon>' in Table '<ccon>BI-Inventory Levels</ccon>' contains a duplicate value '<ccon>401W47</ccon>' and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table. Table: BI-Inventory Levels.

[rubayatyasmin]

Hi, @darb 

Open Power query and use group by in SKU column and then you will be able to see if there is any duplicated values in your or not. Sometimes there are special characters available in our data that are not printable. So I suggest you perform a trim operation in that column. Then try to refresh. 

Also, do not forget to check the data model if any relationship is creating duplicates or not.