[FIXED BUG] Automatic Let's Encrypt Certificate renewal for securing Plesk fails: empty domain name

Applicable to:

Automatic Let's Encrypt Certificate renewal for securing Plesk fails and following error message can be found in /var/log/plesk/panel.log file:
# egrep "ILLEGAL_ARGUMENT" /var/log/plesk/panel.log
...
ERR [extension/letsencrypt] Failed to renew Panel certificate: idn_to_ascii: empty domain name: U_ILLEGAL_ARGUMENT_ERROR.
...
Renewing manually Let's Encrypt Certificate for securing Plesk going to Tools & Settings > SSL/TLS Certificates > Let's Encrypt > Renew works successfully.

Product issue:

#EXTLETSENC-573 "Decreased the possibility of rare issues when IDN domains could not be secured with SSL/TLS certificates from Let’s Encrypt."
Fixed in:
- Let’s Encrypt 2.9.0 26 March 2020

Please consider updating your server:

If update is not possible for some reason you may try the following

workaround

As a workaround, issue manually a Let's Encrypt Certificate for securing Plesk according to the instructions provided in following KB articles: