When you encounter the error code 400 The Plain Http Request Was Sent To Https Port, it's likely a sign of an issue related to your website hosting setup or configuration. This specific error is often caused by incorrect configuration settings, such as the use of non-HTTP protocol ports (e.g., port 443 for HTTPS) with web servers that do not support HTTPS.
Nginx is a popular web server software often used in conjunction with PHP or other scripting languages. However, when Nginx is configured to use non-HTTP protocol ports (like port 443 for HTTPS), it can lead to this error. To troubleshoot the issue, you may want to check your Nginx configuration file (nginx.conf) and ensure that the HTTP protocol is set correctly.
To verify if your Nginx configuration is the cause of the error, you can use a tool like nmap to scan for open ports. This will help you determine which port is causing the issue.
Here are some steps you can take to resolve the error 400 The Plain Http Request Was Sent To Https Port:1) Check your Nginx configuration file (nginx.conf) for any incorrect protocol settings2) Ensure that your web server is configured to support HTTPS3) Verify that all necessary files and directories are installed and accessible4) Consider upgrading your web hosting plan to one that supports HTTPS
By following these steps, you should be able to identify and resolve the issue causing the error 400 The Plain Http Request Was Sent To Https Port. If you're still experiencing issues after attempting the above solutions, it may be helpful to reach out to your web hosting provider for further assistance.