[2025-07-21] Cannot issue or renew Let's Encrypt certificate for domain: 503 "Service busy; retry later" or 500 "Problem getting authorization" response

Symptoms

• Attempts to issue a Let's Encrypt for a domain results in one of these errors:

  Could not issue an SSL/TLS certificate for example.com
  Details
  Could not issue a Let's Encrypt SSL/TLS certificate for example.com.
  Details
  Invalid response from https://acme-v02.api.letsencrypt.org/acme/order/123456789/123456789012
  Details:
  Type: about:blank
  Status: 503
  Detail: {"type": "urn:ietf:params:acme:error:rateLimited", "detail": "Service busy; retry later."}

  Could not issue an SSL/TLS certificate for example.com
  Details
  Could not issue a Let's Encrypt SSL/TLS certificate for example.com.
  Details
  Invalid response from https://acme-v02.api.letsencrypt.org/acme/authz/123456789/123456789012
  Details:
  Type: urn:ietf:params:acme:error:serverInternal
  Status: 500
  Detail: Problem getting authorization

• One of the following errors can be found in the main Plesk log /var/log/plesk/panel.log:

  [2025-07-21 18:55:25.369] 34887:687e8d1c7b34f ERR [extension/letsencrypt] Domain validation failed: Invalid response from https://acme-v02.api.letsencrypt.org/acme/order/123456789/123456789012
  Details:
  Type: about:blank
  Status: 503
  Detail: {"type": "urn:ietf:params:acme:error:rateLimited", "detail": "Service busy; retry later."}

  [2025-07-21 19:29:03.178] 25040:687e94fe36bc0 ERR [extension/sslit] Error happened while certificate processing : <span class='plesk-ext-letsencrypt--secure-domain-issue-certificate-error' hidden></span>Could not issue a Let's Encrypt SSL/TLS certificate for <b>example.com</b>.
  <br/><span class='plesk-ext-letsencrypt--details-toggler' data-details-content-id='plesk-ext-letsencrypt--details-content-3ZIQud1bTL4aFQx7' onclick='PleskExt.Letsencrypt.toggleCollapsibleDetails(this); return false;'>Details</span><div class='plesk-ext-letsencrypt--details-content' id='plesk-ext-letsencrypt--details-content-3ZIQud1bTL4aFQx7' style='display: none'>Invalid response from https://acme-v02.api.letsencrypt.org/acme/authz/123456789/123456789012<br />
  Details:<br />
  Type: urn:ietf:params:acme:error:serverInternal<br />
  Status: 500<br />
  Detail: Problem getting authorization</div><br/>

Cause

The Let's Encrypt API is experiencing an outage.

Resolution

Check the Let's Encrypt status:

https://letsencrypt.status.io/

Once the API outage is over, try to issue the certificate anew. Subscribe using the button on the status page for updates.