Not able to create return from dashboard and from API as well

Here is the API response: {“errors”:[{“message”:“Unexpected Error”,“operation”:“return_create”,“field”:“return_create”,“request_id”:“6908a807f98f1f4474d2e30c”,“code”:22}],“data”:{“return_create”:null},“extensions”:{“throttling”:{“estimated_complexity”:10,“cost”:10,“cost_detail”:{“return_create”:{“items_count”:0,“cost”:10,“total_cost”:10,“fields”:{}}},“user_quota”:{“credits_remaining”:4004,“max_available”:4004,“increment_rate”:60}}}}

Please find the error I am getting from dashboard:

Error! Failed to Generate RMA. ‘NoneType’ object has no attribute ‘assigned_warehous

Hello, please direct this inquiry to support@shiphero.com. From there they will best be able to assist with errors like this with access to logs related to your user and account. When submitting the inquiry please include the full request body.