3416470 - Error: Ref ID for Return DEF is not valid. Enter a valid ref ID.

While opening the Customer Return, system shows the error messages

"Sales Order reference with ID ABC not valid" (ABC represents the Sales Order ID)

"Ref ID for Return DEF is not valid. Enter a valid ref ID." (DEF represents the Return ID)

Item XX: Copying item XX not possible; configuration from Product - project-based to missing (XX represents the line item number).

SAP Business ByDesign

1) Go to the Sales Orders -> Returns. 

2) Edit Return DEF 

error messages

"Sales Order reference with ID ABC not valid"

"Ref ID for Return DEF is not valid. Enter a valid ref ID."

"Item XX: Copying item XX not possible; configuration from Product - project-based to missing"

Business ByDesign does not support Item Type PMAT - Product - Project based in the Customer Return scenario and the Customer return DEF is created based on the Outbound Delivery. And the Outbound Delivery is created from Project Stock Order with Item Type Pre-Delivery. In order to return a pre-delivered product to the warehouse which is related to a project, you have to remove the link to the project in inventory first and then only create a Customer Return. 

To solve the issue you need to:

1. Make the Return consistent by assigning an external Reference. 
   1. Go to the Sales Orders work center.
   2. Select the Returns view.
   3. Open return DEF.
   4. Navigate to the Items tab.
   5. Select the Line Item and press the Assign Reference button.
   6. In the Assign Reference window activate the External Indicator.
   7. Enter the Reference Type Sales Order, a Reference ID and a Reference Line.
   8. Press the OK button.
      
      
2. Cancel the Return. 
   You can follow the steps provided in KBA "2936830 - How to Cancel a Customer Return" 
   
   
3. Remove the link to the project in inventory first and then create a new Customer Return. 
   You can refer to the blog "Product returns from projects to inventory" (Product returns from projects to inventory | SAP Blogs )

Product returns from projects to inventory | SAP Blogs

2936830 - How to Cancel a Customer Return

PMAT; Return; configuration from Product - project-based to missing; Project Stock Order; Reference; invalid; not valid; Enter a valid ref ID; Project; Sales Order;  , KBA , AP-CRP , Customer Return Processing , Problem