Unable to renew Let's Encrypt certificate in Plesk: 403 Forbidden

Applicable to:

Let's Encrypt certificates fails to be issues or auto-renewed with the following error in Plesk UI on a Linux server:

PLESK_ERROR: Status: 403
Detail:
<head><title>403 Forbidden</title></head>
<body bgcolor="white">
<center><h1>403 Forbidden</h1></center>
<hr><center>"

Or in Plesk on Windows server:

PLESK_ERROR: Details:
Type: urn:acme:error:unauthorized
Status: 403
Detail: Invalid response from http://example.com/.well-known/acme-challenge/WTAKI-FRel8tZZKYyhM2UfzvM9TWk02r4fZ__cjuCkU:
Website shows "403 Forbidden" error.
Deny directive is set in additional nginx or Apache directives in Domains > example.com > Apache & nginx Settings, e.g:

CONFIG_TEXT: location ~ /\. {
deny all;
}
The following entries appear in /var/www/vhosts/system/example.com/logs/proxy_error_log :

CONFIG_TEXT: [error] 11940#0: *46281 access forbidden by rule, client: 203.0.113.2, server: example.com, request: "GET /.well-known/assetlinks.json HTTP/1.1", host: "example.com"

Communication between website and Let's Encrypt servers is prevented by restrictive web server settings.

For Linux servers

Log into Plesk.
Open Domains > example.com > Apache & nginx Settings:
- Temporary remove deny directives from Additional Apache directives and Additional Nginx directives.
- Set Deny access to the site to Default under Common Apache settings:

For Windows servers