I keep getting that message while watching Netflix on Apple TV and when I tested my Wi-Fi on Apple TV and when I checked to see if my internet was doing good also and no problem. Is the Apple servers down or Netflix?
What does the message say exactly?
Since you're relying on memory, can you get it to do it again and tell us what it says? I've seen mine have network issues before, it's been a long time, but I don't ever recall seeing anything like what you're describing.
Do you have adequate cooling around the unit? If you have it stacked on other heat producing components it can have negative affects on performance, including network and speed issues.
Okay then... how about the connection itself. Is it wireless to the ATV or wired with Ethernet? If it's wireless, try connecting it via Ethernet and see how the performance play out. Maybe, just maybe, there is too much wireless interference that is causing issues. That's about all I can think of now.
How about swapping out the router and/or modem with different ones. There could be an issue with one of those devices.
My ISP checked my modem and said everything is fine, as for my Airport Extreme it is 4th Gen and my Express is the latest gen. Not sure which I would need to swap if I can not tell which is the problem. How can I check to see if my cable modem is working correctly? I see all the lights on it working correctly.