First create a field assignment in Customizing in system &1

What causes this issue?

You want to transfer data from a BW query to Profitability Analysis.
For this, you need to make a field assignment between the BW query
fields and the operating concern.

System Response

The data transfer cannot occur without the field assignment.

How to fix this error?

Under <DS:SIMG.RETRAKTOR_CUST>Specify field assignment</>, you can set
up this field assignment in Customizing for transferring data from SAP
BW to Profitability Analysis.
Note
The IMG for data transfers from SAP BW to Profitability Analysis has
its own structure. You can include it for easier access in the standard
IMG for Profitability Analysis. For more information, see note 205201.

Error message extract from SAP system. Copyright SAP SE.