The below issue is now reported as resolved in both the Education Community & Subscription Center
We are currently experiencing an issue in the Education Community and the Subscription Center which is preventing the availability to download certain products. As a temporary workaround, please either utilize our Trials page (for 2013 software) or the Student Facebook site to obtain a download link. AutoCAD 2013 can be downloaded directly from the links posted below. We apologize for the inconvenience and thank you very much for your patience.
Clicking these links will initiate download of the product:
AutoCAD 2013 32-bit
AutoCAD 2013 64-bit
Camilo Lemos