Some of these are caused by Samsung services being out. Only they can tell you and sometimes they don't know. There is no up or down page by Samsung (huge oversight in my opinion.)
Also, sometimes they need to use remote management to fix this.
Yes you can check if your TV firmware is current and try a factory reset but this and other reasons I just disable Smart Hub and never look back. Why Samsung tracks your TV use is why.
smart hub version 4.6261
When I try to sign into smart hub, each time it ways that I have lost connection. Then I can cancel the login, or retry. If I retry, the same thing comes up. Is there anyway that I can fix this without contacting Samsung(lets be honest, they're a pain)