At this point, with that error still showing up, I would perform a factory reset on the unit. You can use the article below to do so:
This should fix the W-200 error. If it doesn't, please let us know.
My Slingbox worked fine until recently. Now I get the W200 error. After googling solutions, I made sure all my cables were fully plugged in, the power and networking lights were on and solid, and enabled port forwarding on my router. Nothing worked. What else can I do? Thanks.