Please check the following points in advance:

• Was the event action of the shipping notification triggered after the creation of the return label?
• Is there a return label for every parcel number?
• Are all shipping service providers correctly linked for Otto Market in the assistant?
• Does the return service provider configured in PlentyONE match the one in the OPC of Otto Market?
• Are the addresses of your warehouse correct?
• If you use DHL: Are your login details up to date?

To find a solution more quickly, we recommend searching the log for error messages.