Symptoms
- 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.
Cause
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
Resolution
Please consider updating your server:
Workaround
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: