In the spirit of xkcd 979, let me describe something that recently happened.
My PS4 could not log into PSN, the PlayStation Network. It would show various error codes:
Then I logged out, and tried to log in by inputting the password. I saw a new error code:
I tried logging into PSN from my laptop, from the same home network. I saw:
This page can't be displayed. Contact support for additional information.
The incident ID is: N/A.
Sometimes I’d see a long incident number. It would change with each attempt.
I called the PlayStation support center. They didn’t have any information about the error codes I saw. They checked that my IP address was not blocked. They suggested setting up port forwarding. I thought it would be an odd way of dealing with the logging in problem.
I rang up my ISP. The support person said that there’s a problem with my broadband connection and they’re going to send a technician. The technician detected that some cable outside of my house got rusty and the signal level went down from -1dB to -11dB. The technician fixed this. I waited maybe 3 days and my PS4 started logging into PSN without problems.
So, what was it? Why a weak broadband connection would result in PSN refusing logins from my home network? I don’t know! I could speculate but I have so little information that I would be almost certainly wrong.