Review the Symantec Cloud Adminstrator Guide (link provided in the thread Brian shows above).
You may simply need to enable File and Printer Sharing, which is turned off by default.
If that doesn't work review the section/chapter on Configuring Firewall Rules.
You can either indicate the IP address of your AIO, or the specific port that needs to be open to allow the device to reach the server.
Hope that helps!