This incident has been resolved.
Stamps.com Engineers have identified an issue that may temporarily affect some of our customers' ability to print postage and shipping labels. We are working to quickly resolve this issue and will provide an update when it is available. We apologize for the inconvenience.
This incident affected: Stamps.com Online (Printing Postage Using a Web Browser), Stamps.com Software (Printing Postage Using our Windows Application), and Stamps.com API (SWS/Web Services).