A website behind Cloudflare shows the following error message in a web-browser:
PLESK_INFO: The page isn’t redirecting properly
When Cloudflare is disabled, the website loads fine.
The Permanent SEO-safe 301 redirect from HTTP to HTTPS setting is enabled in Plesk at Domains > example.com > Hosting Settings or custom HTTPS redirection is configured in domain’s .htaccess file.
The SSL setting is set as “Flexible” in Cloudflare Crypto settings for this domain.
Log in to your Cloudflare account > click on the domain > click Crypto and change the SSL setting to “Full (strict)”.
Note: The CloudFlare account is created automatically during the initial activation of the extension. Since the CloudFlare extension is enabled on the server, the corresponding account on a CloudFlare side already exists. If the account credentials are forgotten, try to recover the password via the following link to access Cloudflare dashboard: https://www.cloudflare.com/a/forgot-password
The same email should be specified as for the initial extension setup.