Sorry to hear your having an issue networking your Slingbox. Have you recently changed routers or made some other change to your home network? There may be some settings you'll need to adjust within your router. It could also have something to do with your firewall or proxy settings. Here is an article from our support page regarding error messages you receive on Watch on Slingbox.com, Understanding Watch on Slingbox.com error codes.
Also, here is another article which describes your issue as well, Watch on Slingbox.com says "Unable to connect" and/or won't work at my office.
I hope this information will help you with this issue!
The Sling Media Moderation Team