E-Ship Error

We have been using NAV for sometime now but just recently having problems during Manifest of FedEx packages.

We currently ship FedEx packages with e-ship through the FedEx API. After receiving all labels and sending it out on the FedEx truck, we post the order. When attempting to post the manifest, the following error appears:

error closing FEDEX account xxxxxxxxx:

according to fedex, they are not receiving the manifest. can someone help me out with this?