"This page is currently offline"

Last night, a client reported that his website suddenly went offline responding with a Kirby error message:

This page is currently offline. We are very sorry for the inconvenience and will fix it as soon as possible.

Advice for developers and administrators:
Upgrade PHP to 7.1+

The server is using PHP 7.2 so this message is a bit strange.
We didn’t encounter the error ourselves: right now everything is working fine again.

So we are trying to investigate this:
Is there any case where Kirby might throw this error message other then an unmet PHP requirement?

The only place where this view is called is in bootstrap.php:

if (version_compare(phpversion(), '7.1.0', '>=') === false) {
    die(include __DIR__ . '/views/php.php');

Who controls the server? Maybe there were some changes on the server last night?

Thanks for verifying, Sonja!

The site is hosted by GreenGeeks, https://www.greengeeks.com. They offer cPanel access and the PHP version is set correctly (it was earlier this week and it is right now).

I’m waiting for feedback from our client now. But this really looks like a server issue then.

Did you verify that the PHP version is actually 7.1+ with a phpinfo call? I often had the situation where everything looked like the right PHP version was running, but in fact in a phpinfo call another version turned up.

I will do that, if this occurs again. The site ran without issues two days ago and it does now. So something must have been changed in-between (we didn’t touch the server).