Red triangle – This site cannot be accessed. Disconnect Site.

WordPress…WHY.
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Hello,

I’ve looked at a few threads in this forum but haven’t been able to find a solution..
https://wp.finnishwaterforum.fi/en/

This is the link to the website.

There is that red triangle and if you click on it, it says
This site cannot be accessed. Disconnect Site.

Jetpack has disappeared.
I wonder if it will make a difference if acccessing FTP, deleting file and reinstalling it?

But I was unsure of the main core of the problem..

The site still opens for some reason so it’s not the worst problem..but if this could be easily solved, I would be very much grateful.

Jini