Https just stopped working

[weqwer19]

I faced a problem with many of my websites using Let's Encrypt.
On chrome I got Err_Connection_Closed
They did not work with any browser.
It did happen on 3 different servers.

The problem was fixed after creating a new certificate.

It happened for:
https://gosolar.gr
https://nikiamarousiou.gr
https://ear-books.com
https://tora-elastika.gr

What should I do?

My domain is: https://ear-books.com
I ran this command: renew
It produced this output: renewed successfully
My web server is (include version): Apache 2.4.25
The operating system my web server runs on is (include version): CentOS 6.9
My hosting provider, if applicable, is: kapaweb.gr
I can login to a root shell on my machine (yes or no, or I don't know): yes
I'm using a control panel to manage my site (no, or provide the name and version of the control panel): directadmin

[rg305]

It sounds like your sites had trouble that was fixed by renewing expired certificates.
If so, renewing certs is something you have to handle.
They won't automatically renew on their own.

You could setup a cron job that will attempt to renew on a schedule (like daily or weekly).

[weqwer19]

There is a cron automatically renewing the certs 1 month before expiry,
but that is not the point.
That's not a solution. If a cert is expiring in 2 months, why does it stop working now?

[rg305]

I don't follow.
How/when did it stop working?
Which cert expires in two months?

I do see that you have .com and .gr domains.
But they are not both going to the same vhost.
For instance:
https://ear-books.com works without issue.
however,
https://ear-books.gr fails cert check because the cert used is:

[weqwer19]

Let take ear-books.com for example.
I issued the certificate 15/06/2017 and for some reason on 18/06/2017 no-one was able to visit the page because of it.

I already know that issuing a new cert is a walk-around the problem (not a solution),
but we should be looking at why this happened and how to prevent it from happening again.

[rg305]

Maybe you changed something...

The cert from April shows:
DNS:ear-books.com
DNS:ftp.ear-books.com
DNS:mail.ear-books.com
DNS:pop.ear-books.com
DNS:smtp.ear-books.com
DNS:www.ear-books.com
https://crt.sh/?id=116809701

The cert from June shows:
DNS:ear-books.com
DNS:ear-books.gr
DNS:ftp.ear-books.com
DNS:ftp.ear-books.gr
DNS:mail.ear-books.com
DNS:mail.ear-books.gr
DNS:pop.ear-books.com
DNS:pop.ear-books.gr
DNS:smtp.ear-books.com
DNS:smtp.ear-books.gr
DNS:www.ear-books.com
DNS:www.ear-books.gr
https://crt.sh/?id=156644316

for some reason on 18/06/2017 no-one was able to visit the page

Maybe they went to the .gr site (which doesn't work because of misconfiguration NOT certificate)

Please re-read this entire thread.
Some posts may have been updated/edited after your first read.

[weqwer19]

I haven't changed anything to all 4 websites.
And I was not trying to access the .gr domain.

[rg305]

If you can, show the vhost files.