Unable to add SSL certificate using Let's Encrypt.

Hi @all,

I was following this tutorial to install SSL on my droplet. How To Secure Apache with Let’s Encrypt on Ubuntu 16.04

But for some reason I am getting this error: Failed authorization procedure. (tls-sni-01): urn:acme:err or:connection :: The server could not connect to the client to verify the domain :: Connection refused, (tls-sni-01): urn:acme:error:c onnection :: The server could not connect to the client to verify the domain :: Connection refused IMPORTANT NOTES: The following errors were reported by the server: Domain: Type: connection Detail: Connection refused

Domain: Type: connection Detail: Connection refused

To fix these errors, please make sure that your domain name was entered correctly and the DNS A record(s) for that domain contain(s) the right IP address. Additionally, please check that your computer has a publicly routable IP address and that no firewalls are preventing the server from communicating with the client. If you’re using the webroot plugin, you should also verify that you are serving files from the webroot path you provided.

And I have checked the firewall status, here is the ufw status: Status: active To Action From Apache Full ALLOW Anywhere OpenSSH ALLOW Anywhere 80 ALLOW Anywhere 443 ALLOW Anywhere Apache Full (v6) ALLOW Anywhere (v6) OpenSSH (v6) ALLOW Anywhere (v6) 80 (v6) ALLOW Anywhere (v6) 443 (v6) ALLOW Anywhere (v6)

I am doing this first time and had googled but no result. and event tried the cases on tutorial page. still error persists…

Can anyone help?

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Finally was able to install certificates. Had removed mail server related processes which were running previously and this issue is also reported in github. Referred this too: Certbot fails to get certificates under Ubuntu 16.04

thank you for your help and time, really appreciate it.


these are the commands which I had found in history.log file

apt-get install -y dialog


apt-get install -y postfix postfix-pcre mysql-client mysql-server postfix-mysql libdbd-mysql-perl libaprutil1-dbd-mysql php-json php-gd php-mcrypt php-curl mcrypt php-intl php-xml php-mbstring php-mysql apache2 apache2-utils libapache2-mod-php dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-managesieved dovecot-sieve dovecot-mysql amavisd-new libcrypt-openssl-rsa-perl libmail-dkim-perl clamav-freshclam clamav-daemon spamassassin altermime arj zoo nomarch cpio lzop cabextract p7zip rpm ripole libmail-spf-perl unrar-free pax python-sqlalchemy python-dnspython python-mysqldb python-pymysql python-jinja2 python-netifaces python-webpy python-beautifulsoup python-lxml python-pycurl libapache2-mod-wsgi python-bcrypt awstats fail2ban bzip2 acl patch cron tofrodos logwatch unzip bsdutils liblz4-tool

I think the former command was the result of the sudo bash command which I used from the tutorial Not sure but these are the commands shown there.


Bam! There it was:

[crit] Memory allocation failed, aborting process.

You’re running out of RAM on the server, which is why it was misbehaving in a very strange way. This is because you installed a lot of services to run a mail server. There’s not quite enough resources on a 1GB droplet to sustain so many services.

You need to reinstall the entire droplet or uninstall every single service you don’t use. Since I don’t know which tutorial you followed to install the mail server, then I don’t know which services to uninstall.