invoice osclass CURL error when generating PDF: [6] Could not resolve; Unknown error

This is how my pdf attachment looks like.

Ideas?

Have unninstalled the Plugin, deleted then reinstall still having the same issue.. what could be? where the issue may come from?

Fix...

1. First, we log in via SSH and edit /etc/resolv.conf.

vi /etc/resolv.conf
2. Next, we add Google public name servers and comment on the other nameservers.

nameserver 8.8.8.8
nameserver 8.8.4.4
#nameserver 1xx.1xx.1xx.x
#nameserver 1xx.1xx.1xx.x
3. Then after making the changes, we restart Apache or Nginx.

service apache2 restart

Thanks for feedback.
That error means simply plugin could not call its pages.

Yes,. you are right. It also happens when I put back my domain in cloudflare. Once it's out the plugin works back. Any idea what could be?

No its simply connectivity problem of curl

ahh yes, curl and possibly an invalid / unsigned cert that is failing origin authentication. Do you have verify origin certs enabled in CF? I'd look there first. You should be able to see what the issue is by looking at the logs.