I have tried printing a DHL Parcel UK shipping label and am seeing an error returned:

Validation failed. Invalid Consignment Booking. 


Please make sure 'Defer service' option is disabled in the service config and the 'deferred days' amount is set to 0:

If you wish to use Defer service and the current amount of deferred days is set to 0, please get in touch with your DHL Parcel UK account manager to make sure this option is available for your account.