We recently discovered a bug in the Let's Encrypt certificate authority code, described here:
Unfortunately, this means that certificates that were affected by this bug will be revoked by the certificate authority.
To avoid disruption, you'll need to renew and replace your affected certificate(s) by Wednesday, March 4, 2020. IF your certificate is affected.
If your certificate is affected, the fix is simple. Just log into your account, go to the Plesk login, click on the SSL certificate icon then click "renew certificate". The certificate will be automatically renewed.
We sincerely apologize for the issue.
Tuesday, March 3, 2020