This error messages has to do with the configured volume and/or load factor. Please check the following points:

• Is the sender the right address? 
• Is the receiver the right address? And does this carrier go there?
• Is the weight of the shipment within the maximum weight the carrier will ship?

If this doesn't help, please contact our support department via a new ticket. They can check the configuration and, if necessary, edit this. Please send an example reference with this error so our support team can help you faster.