Hello, I'm sorry to hear about the trouble. Have you ensured that the firmware is completely up to date on the unit? This would be the first step for this error, it to make sure it's completely up to date.
(Find steps here: https://www.samsung.com/us/support/answer/ANS00062224/)
If it is up to date, and you're still getting the error, you stated you tried a reboot, but have you tried a factory reset of the television?
(find steps here: https://www.samsung.com/us/support/answer/ANS00077524/)
The next question is to ask what model Television you would have and is it in the proper region. If you take a unit outside of the country it's manufactured for this error can sometimes occurred, as we cannot guarantee that the smart hub or applications will work if it's taken out of the country of origin it's manufactured for. You can google the model code and based on your results, you can normally tell if a unit is manufactured for the US or a different country.
(fyi - Model codes ending in "XZA" are US Models)
Also, you can check with your Internet Service provider for assistance, Make sure there's no mac filters or anything in the router settings that could be blocking you from accessing the servers.