Comprehending the WordPress Alert: Absence of sunrise.php File

If you’re overseeing a WordPress multisite and come across the following alert:

Alert: include_once(/home/u801461719/domains/scienceblog.com/public_html/wp-content/sunrise.php): Failed to open stream: No such file or directory in /home/u801461719/domains/scienceblog.com/public_html/wp-includes/ms-settings.php on line 47
Alert: include_once(): Failed opening '/home/u801461719/domains/scienceblog.com/public_html/wp-content/sunrise.php' for inclusion (include_path='.:/opt/alt/php82/usr/share/pear:/opt/alt/php82/usr/share/php:/usr/share/pear:/usr/share/php') in /home/u801461719/domains/scienceblog.com/public_html/wp-includes/ms-settings.php on line 47

…it’s crucial to recognize its significance and how to resolve the situation. This article clarifies the problem, outlines typical reasons, and offers guidance on potential fixes.

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What Does sunrise.php Represent?

The sunrise.php file is a unique configuration file utilized in WordPress Multisite (particularly in domain-mapped multisite architectures) to oversee domain mapping and site initialization during the initial phases of site loading. It’s invoked within the core WordPress file ms-settings.php, which manages network/multisite settings.

In a standard WordPress setup, the sunrise.php file is not present by default. Its existence is necessary only for specialized multisite features.

Primary Functions of sunrise.php

– Domain mapping within multisite networks, mainly in previous setups from before WordPress 4.5.
– Custom processing before the entire multisite system initializes.
– Complex site routing needs.

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What Is Causing This Alert?

The alert appears due to a code line in the ms-settings.php file trying to load the sunrise.php file:

include_once( WP_CONTENT_DIR . '/sunrise.php' );

However, since WordPress cannot find the file, it triggers the following alerts:

– include_once(): Failed to open stream
– include_once(): Failed opening for inclusion

These indicate that WordPress has been directed to include a non-existent file in the given directory.

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Frequent Reasons

1. The sunrise.php file is genuinely absent.
— This is the most direct reason. It’s possible that someone removed the file or it was never added if you aren’t utilizing any specialized domain mapping features.

2. Incorrect setup of multisite installation or domain mapping plugin.
— If you activated sunrise mode in wp-config.php using:

define( 'SUNRISE', 'on' );

— WordPress will look for the sunrise.php file in wp-content/. Its absence leads to the alert appearing.

3. Errors in file permissions or paths.
— The file may exist, yet be unreachable because of permission problems or incorrect file paths.

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How to Resolve the sunrise.php Alert

Depending on your scenario, there are several methods to address the problem:

1. If Domain Mapping Is Not Needed

If you’re not utilizing any plugins or custom scripts that depend on sunrise.php, you can simply turn off the sunrise configuration in wp-config.php:

// Comment out or eliminate this line if not necessary
// define('SUNRISE', 'on');

Save the document and refresh your website — the alert should no longer appear.

2. If Using a Domain Mapping Plugin

Many domain mapping plugins, such as the older “WordPress MU Domain Mapping” plugin, necessitate the presence of the sunrise.php file.

✅ Steps to resolve:

– Verify that the plugin is installed correctly.
– Find the sunrise.php file in the plugin’s directory (often located under /wp-content/plugins/).
– Copy it to /wp-content/:

cp wp-content/plugins/your-plugin-folder/sunrise.php wp-content/sunrise.php

– Ensure this