There are a few things that could cause a W200 error message. Check your Slingbox to make sure that both red lights (Network and Power) on its right-front are lit. If both lights are out, make sure the Slingbox is receiving power. If the left light is out or blinking, check all network cables and make sure your Slingbox is connected to your router. In general, it's a good idea to just do a full reset on your Slingbox.
Here the instructions for a reset: How to reset your Slingbox to factory settings
Let me know if that helps,