/rs/soap/shipment/v8 (…) element mobo value (…) is not a valid instance of type CustomerIDType [Solution]

When processing orders, you might come across the "/rs/soap/shipment/v8 (…) element mobo value (…) is not a valid instance of type CustomerIDType" error. 

Feel free to follow the step-by-step guide written below or the video guide, as you prefer: 

To solve this issue you will have to:

1. Access Clients under the Maintenance menu
   
   
   
   
2. Click on the client related to the order
   
   
3. Edit the Billing Account related to the order and error
   
   
   
   
4. Select the Carrier Options tab
   
   
5. Verify that the information entered in the Paid by Customer # is correct, or if empty, complete it (usually, with the Customer # without the filler zeroes at the left)
   
   
   
6. Press Save to apply the changes