Let's Encrypt failed Auto renewal

I have 3 servers that since updating have started snowing a few issues.

One that I noticed this morning is that Let’s Encrypt is failing to auto renew. This is the email I get:

An error occurred requesting a new certificate for www.domainnamehere.co.uk from Let’s Encrypt : Web-based validation failed : Failed to download chained certificate : Failed to lookup IP address for letsencrypt.org
DNS-based validation failed : Failed to request certificate :

Gave up waiting for validation

Can anybody suggest anything I can do?
Can these be manually renewed?

A very quick update, running this allows me to renew manually.

virtualmin generate-letsencrypt-cert --domain yourdomain.com

I have two servers doing the same from 2018 april/may…
Do you have a solution?

I used certbot from let’s encrypt, but had to rename the received certificate/key to ssl.cert, ssl.key to work with dovecot, etc…

Virtualmin admins: what happened with auto renewal?

I restarted webmin and it sorted all whatever the issue was.

Good luck!