Website is not accessible: 404 Not Found

Symptoms

Website is not accessible:

• Firefox: Server not found
• Opera: Could not locate remote server
• Internet Explorer: Internet Explorer cannot display the webpage or shows This page can’t be displayed message
• Google Chrome: This site can’t be reached

Requesting the website over HTTP and shows redirection to HTTPS:

# curl -I http://www.example.com/ -v
* About to connect() to www.example.com port 80 (#0)
*  Trying 203.0.113.2... connected
.........
< Location: https://www.example.com/
Location: https://www.example.com/​   
< Server: Microsoft-IIS/7.5
Server: Microsoft-IIS/7.5

Requesting the website over HTTP shows SSL connection error:

# curl -k https://www.example.com/ -v
* About to connect() to www.example.com port 443 (#0)
*  Trying 203.0.113.2... connected
* Connected to www.example.com (203.0.113.2) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* warning: ignoring value of ssl.verifyhost
* skipping SSL peer certificate verification 

Cause

Redirection to HTTPS is hardcoded in website code, but not enabled in Plesk.

Resolution

Note: if you don't have administrative access to Plesk server via SSH or RDP, contact your hosting provider regarding the issue

1. Login to the server over SSH or RDP

2. Go to Subscriptions > example.com > Domains & Websites > Hosting Settings and enable 'SSL\TLS support' option: