Error: Let's Encrypt validation status 400

[rogero]

Many domain names get Error: Let's Encrypt validation status 400 Some are automatically renewed after migration to new server with myvestacp. But new and other domain names are not getting renewed

[dpeca]

You need correctly configured DNS.

If you are using your own nameservers,then:

• In your DNS you have NS1 and NS2 as A record that is pointing to IPv4 of your server
• NS1 and NS2 are registered as Nameservers at register of your domain.

If you are using other DNS,then:

• Double check if both www and non-www is pointing to your IPv4 - use https://mxtoolbox.com/DNSLookup.aspx for checking
• Remove AAAA records in DNS - use https://mxtoolbox.com/IPv6.aspx for checking (should return "DNS Record not found")

CloudFlare is exception, it will return it's own IPv4 and IPv6, and that's fine.