WPCode Fatal Error During Modular DS OAuth on WordPress Multisite

I found a reproducible compatibility issue between WPCode and Modular DS on a WordPress multisite installation. Environment

• WordPress multisite
• PHP 8.2
• WPCode version 2.3.8
• WPCode network-activated
• Modular Connector version 3.0.2
• nginx
• Cloudflare
• Modular DS connects through a request to:

/wp-load.php?code=...&origin=mo&type=oauth

Problem

When WPCode is network-active, the Modular DS OAuth request returns HTTP 500.

The exact fatal recorded by Modular Connector is:

production.ERROR: Class "WPCode_File_Cache" not found

Error location:
wp-content/plugins/insert-headers-and-footers/ihaf.php:436

Stack trace:

#0 wp-includes/class-wp-hook.php(341): WPCode->load_components()
#1 wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters()
#2 wp-includes/plugin.php(522): WP_Hook->do_action()
#3 wp-settings.php(622): do_action()
#4 wp-config.php: require_once(...)
#5 wp-load.php: require_once(...)

After manually preloading that class, the fatal advances to other WPCode admin-only classes, including:

Class "WPCode_Library" not found
Class "WPCode_Admin_Page_Loader_Lite" not found
Class "WPCode_Smart_Tags_Lite" not found

Apparent cause

In ihaf.php, WPCode loads admin-only class files inside this condition:

if ( is_admin() || ( defined( 'DOING_CRON' ) && DOING_CRON ) ) {
	require_once WPCODE_PLUGIN_PATH . 'includes/class-wpcode-file-cache.php';
	require_once WPCODE_PLUGIN_PATH . 'includes/class-wpcode-library.php';
	// Other admin classes...
}

Later, WPCode::load_components() uses the same condition and instantiates those classes:

if ( is_admin() || ( defined( 'DOING_CRON' ) && DOING_CRON ) ) {
	$this->file_cache   = new WPCode_File_Cache();
	$this->library      = new WPCode_Library();
	$this->library_auth = new WPCode_Library_Auth();
	// Other admin components...
}

Modular DS initially enters through wp-load.php, so is_admin() appears to be false when WPCode runs its includes() method.

Modular Connector later defines WP_ADMIN during its request pipeline. By the time WPCode’s load_components() callback runs on plugins_loaded, is_admin() is true, so WPCode tries to instantiate admin classes that were skipped earlier.

This creates a state mismatch:

WPCode includes phase:
is_admin() = false
Admin files are not loaded

WPCode load_components phase:
is_admin() = true
Admin classes are instantiated
Fatal: class not found

Reproduction

1. Network-activate WPCode.
2. Start a Modular DS OAuth connection.
3. Modular requests:

/wp-load.php?code=...&origin=mo&type=oauth

4. The request returns HTTP 500.
5. The WPCode class-not-found fatal is logged.

Confirmation

When WPCode is network-deactivated, Modular DS connects successfully immediately.

Reinstalling WPCode 2.3.8 did not resolve the issue. Suggested fix

WPCode should avoid evaluating is_admin() independently during two different bootstrap stages.

Possible fixes may include:

• loading all classes required by load_components() unconditionally;
• storing the initial admin-state decision and using the same value in both includes() and load_components();
• checking that each class exists before instantiating it;
• moving the admin includes into load_components() immediately before instantiation.

For example:

if ( is_admin() || ( defined( 'DOING_CRON' ) && DOING_CRON ) ) {
	if ( ! class_exists( 'WPCode_File_Cache', false ) ) {
		require_once WPCODE_PLUGIN_PATH . 'includes/class-wpcode-file-cache.php';
	}

	$this->file_cache = new WPCode_File_Cache();
}

Please let me know if you need the full Modular Connector log or additional server details.