shop4you.hu has AAAA record so Let’s Encrypt will tryi to validate it using this record but your server is not accesible using the advertised IPv6 address
$ curl -IkLv6 shop4you.hu
* Rebuilt URL to: shop4you.hu/
* Trying 2001:470:1f1a:d7::13...
* TCP_NODELAY set
* connect to 2001:470:1f1a:d7::13 port 80 failed: Connection timed out
* Failed to connect to shop4you.hu port 80: Connection timed out
* Closing connection 0
curl: (7) Failed to connect to shop4you.hu port 80: Connection timed out
Domain www.shop4you.com has no obvious DNS configuration issues so no idea why Let’s Encrypt can’t reach your server, maybe you could post the output of
www.born2host.com, root servers are advertising 5 authoritative nameservers:
dig @a.gtld-servers.net born2host.com ns +norec
; <<>> DiG 9.11.1 <<>> @a.gtld-servers.net born2host.com ns +norec
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55237
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 6
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;born2host.com. IN NS
;; AUTHORITY SECTION:
born2host.com. 172800 IN NS ns1.born2host.com.
born2host.com. 172800 IN NS ns2.born2host.com.
born2host.com. 172800 IN NS ns3.born2host.com.
born2host.com. 172800 IN NS ns4.born2host.com.
born2host.com. 172800 IN NS ns5.born2host.com.
;; ADDITIONAL SECTION:
ns1.born2host.com. 172800 IN A 22.214.171.124
ns2.born2host.com. 172800 IN A 126.96.36.199
ns3.born2host.com. 172800 IN A 188.8.131.52
ns4.born2host.com. 172800 IN A 184.108.40.206
ns5.born2host.com. 172800 IN A 220.127.116.11
;; Query time: 11 msec
;; SERVER: 2001:503:a83e::2:30#53(2001:503:a83e::2:30)
;; WHEN: Sun Dec 31 10:54:44 CET 2017
;; MSG SIZE rcvd: 212
But your DNS servers don’t have an A record defined for ns3, ns4 and ns5, also, your dns servers only show ns1 and ns2 as the right dns servers for the domain.
The problemn are not the certificates, you could get them from crt.sh site, for example, in this link https://crt.sh/?id=272548664 you will see the last certificate issued for
shop4you.hu that covers
www.shop4you.hu and in that page, if you click on the link Certificate: you will get the certificate but as I said, that is not the problem, the problem is the private key that is not saved in any place but your server and if you deleted it, that certificate is useless.
As you are using VestaCP… did you try to use their Let’s Encrypt plugin to get your certs?.
I’m sorry but I’m leaving right now so I doubt I can answer to this post till next year but maybe other community buddies could follow it if you resolve your DNS issues and provide the Let’s Encrypt logs.
Good luck and Happy New Year