The network tray icon is not really a good indicator anymore. Microsoft insists on only checking against their own servers to confirm your (wired) internet connection is OK or not. The amount of times I have seen that icon go from one state to the other, for example, while watching Youtube videos (without a glitch)...makes it unreliable.
Of course, there is some logic behind that connection state verification. And you might find the logic compelling. For me, the usefulness of that icon has diminished significantly. It used to be that the icon would flash whenever internet traffic was flowing. But that was removed in Vista/Windows 7. And with Windows 10 it indicates your network settings are incorrect when it cannot connect to Microsoft servers.
In Contro's case, the error message complains about a certificate mismatch. You are visiting a website that uses an incorrect certificate. There is a difference between the (domain) name of the web-site and the (domain) name configured in the certificate that this website uses. An error that is not related to being connected to the internet. The required certificates for such a check are available locally.
This is an error that appears to be generated by a form that Contro is using (to fill in some data, I assume). And such an error on a public WiFi hotspot is a very bad thing. Public WiFi should not used whenever you wish to transmit any important data, such as credit card numbers, your personal registration numbers that your government has coupled to your name, identification numbers of your official documents etc. Public WiFi cannot be trusted in any circumstance. The error you see in the screenshots is your computer warning you about doing something really dumb and potentially very costly (both financially and time-consuming).
Stop doing what you are doing when you see that error, especially on a public WiFi hotspot. If you are not on a public hotspot, you should also stop what you are doing and inform the site owner about this error. Only continue when they tell you it is fixed.
Using certificates is a good way to protect data being transferred over insecure lines, such as the internet. But only when those are properly applied.
The error window are using evernote app on my laptop. I detect with windows explorer.
When this window appear happen I have failed the wifi connection. Only appear when I have lost the wifi connection. It seems to me that evernote app try to connect with its server and show that message if not found.
So is a normal window of error and the wifi connection may be in general unsafe , but in this case is just because the wifi internet connection fails.
I assume you don't know about a reliable indicator for my purpose.
I am using rainmeter some years ago, but I must see the desktop and difficult to detect the internet wifi quality if you are not uploading or downloading.
With uTorrent I quickly detect if the wifi connection is down.
"In Contro's case, the error message complains about a certificate mismatch. You are visiting a website that uses an incorrect certificate. There is a difference between the (domain) name of the web-site and the (domain) name configured in the certificate that this website uses. An error that is not related to being connected to the internet. The required certificates for such a check are available locally." . This affirmation is not correct. Simply the connection is lost and the evernote app tries to reconnect or something similar.
I observed this also recharging some webs. If the connection has failed I received the message a safe connection is not possible. But when the wifi is up those webs loads correctly.
Some webs like Sputnik News, Ali Express and a few others give me problems with this wifi connection. But I solve by another means. No problem with Amazon, Ebay and many others. I have observed some problems with the combination of Firefox and official or gubernamental webs. Sometimes may be a problem similar to that with Ali Express ....
Anyway. I continue trying to find a good app for establish when I am up or down....