Errors messages in settings page

The function that generete the error (setting.php file from the plugin)

function admin_search_setting_post_types() {

	echo "<div id='admin_search_plugin_setting_post_types'>";

	foreach ( get_post_types( array(), 'object' ) as $post_type ) {
		if ( $post_type -> {'public'} ) {
			echo "<p><label><input type='checkbox' name='admin_search_settings[post_types][]' value='{$post_type -> name}'";

			if ( in_array( $post_type -> name, admin_search_setting( 'post_types' ) ) ) {
				echo " checked";
			}

			echo "> {$post_type -> label}</label></p>";
		}
	}

	echo "</div>";

}

This may have something to do with this…

The error message is pretty clear: the in_array() function expects the second parameter to be an array. Instead, it’s receiving a string from that code snippet. If you’re the developer of this plugin you need to add some extra validations to prevent this issue from happening.

From Stackoverflow