Message
The selected unique identifier field is not unique.
Description
The field specified in the Unique identifier parameter must meet the following requirements:
- The field must exist in the feature layer or table to be updated.
- The field must contain all unique values.
- The field must be set as unique in the item details page.
Solution
Go to the item details page for the feature layer or table to update and verify the following:
- The field exists in the feature layer or table.
- The field is set to unique. To learn more about setting unique fields, see Add a unique constraint to a field.
If you're unsure whether the field contains unique values, use the Remove duplicates tool to ensure that all records are unique.