It has been devastating, two weeks ago when connecting to wi-fi a red screen popped up I believe mcAfee symbol of a security safety issue and to go to secured connection. Its been now over two weeks of researching an answer as to why trying to make a connection with home wifi, connects briefly then turns off to a saved secured setting without wi-fi connection. My wife's samsung galaxy note 5, does not have the same problem and is still connected to use the same home wi-fi without issue. There are many answers on the forum, but still not able to have one where one works at home and the other won't. The phone with the issue still can connect while in other wi-fi hot spots. So I believe my phone has got to be the problem in the note 4, but cannot find any system settings within it to correct the issue.