Fatal error: Call to undefined function is_plugin_active_for_network()

The changelog of 5.5 said:

Added compatibility support with WPS Hide Login plugin

But when WPS Hide Login activate, 500 Internal Server Error happens:

PHP Fatal error: Call to undefined function is_plugin_active_for_network() in /htdocs/wp-content/plugins/ag-custom-admin/plugin.php on line 380

The function is_plugin_active_for_network() should be checked before using as follows:

// Makes sure the plugin is defined before trying to use it
if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
    require_once( ABSPATH . '/wp-admin/includes/plugin.php' );
}

Check out https://codex.ww.wp.xz.cn/Function_Reference/is_plugin_active_for_network

https://ww.wp.xz.cn/plugins/ag-custom-admin/