Lightsail Wordpress Getting 404 Not Found nginx/1.18.0 Error

Question

We have a WordPress site running on LightSail, which we've been using actively for the past two weeks without any issues. However, we’re now encountering a "404 Not Found" error with Nginx (version 1.18.0) when trying to access the site. The error appears to have occurred suddenly.

Here are the details of the issue:

- **Website URL**: [http://3.64.185.156/wp-admin](http://3.64.185.156/wp-admin)
- **Error message from Nginx logs**:
  ```
  sudo tail -n 50 /var/log/nginx/error.log
  2025/03/24 03:46:38 [error] 467#467: *3505 client intended to send too large body: 10485761 bytes, client: 185.213.175.171, server: _, request: "POST / HTTP/1.1", host: "3.64.185.156"
  ```
  
- **Nginx configuration test results**:
  ```
  sudo nginx -t
  nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
  nginx: configuration file /etc/nginx/nginx.conf test is successful
  ```

Could you please help us identify why this error is occurring and assist with resolving the issue?

re:Post Agent · Answer

Based on the information provided, it appears that your WordPress site on Lightsail is experiencing a 404 Not Found error with Nginx. This issue can occur due to various reasons, but let's analyze the specific details you've shared.

The error log you provided indicates that a client attempted to send a request body that was too large (10485761 bytes). This suggests that the issue might be related to file upload limits or POST request size restrictions in your Nginx configuration.

Here are some steps you can take to troubleshoot and potentially resolve the issue:

1. Check your Nginx configuration: Although the Nginx configuration test passed, you may want to review your Nginx configuration files to ensure that client_max_body_size is set appropriately. This setting limits the size of the request body that Nginx will accept.

2. WordPress file upload limits: Verify that your WordPress configuration allows for large file uploads. You may need to adjust the upload_max_filesize and post_max_size values in your php.ini file.

3. Examine WordPress core files: Ensure that all WordPress core files are present and have the correct permissions. The 404 error could be due to missing or inaccessible files.

4. Plugin conflicts: Temporarily disable all plugins to see if the issue resolves. If it does, re-enable them one by one to identify any problematic plugins.

5. Theme issues: Switch to a default WordPress theme to rule out any theme-related problems.

6. Reboot the Lightsail instance: Sometimes, a simple reboot can resolve temporary issues.

7. Check file permissions: Ensure that your WordPress files and directories have the correct permissions set.

8. Verify WordPress URL settings: Double-check that your WordPress site URL and home URL settings are correct in the wp-config.php file or the database.

If these steps don't resolve the issue, you may want to consider restoring from a recent backup or snapshot of your Lightsail instance from before the problem occurred. Additionally, if you continue to experience issues, you might need to investigate further by examining more detailed logs or considering a fresh WordPress installation while preserving your content.

Remember to always keep regular backups of your WordPress site and Lightsail instance to make recovery easier in situations like this.
      
**Sources**  
[Lightsail Wordpress Getting 404 Not Found nginx/1.18.0 Error | AWS re:Post](https://repost.aws/questions/QUgEuCnw92RiuNB-MpLZ1HJw/lightsail-wordpress-getting-404-not-found-nginx-1-18-0-error)  
[LightSail Wordpress Error 500 | AWS re:Post](https://repost.aws/questions/QUH5A2vwnxTZOMCCWKbecE3Q/lightsail-wordpress-error-500)  
[Lightsail wordpress admin dashboard show 404 error | AWS re:Post](https://repost.aws/questions/QU3kuOQnM1QzywpAd0U6IkOg/lightsail-wordpress-admin-dashboard-show-404-error)

Lightsail Wordpress Getting 404 Not Found nginx/1.18.0 Error

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