Call to undefined method IndexApp::api_index in file iCMS://app/index/IndexApp.php

1. IndexBoot::init() in iCMS://public/index.php:12 on line 12
2. IndexBoot::start() in iCMS://app/index/IndexBoot.php:12 on line 12
3. IndexRewrite->run() in iCMS://app/index/IndexBoot.php:65 on line 65
4. iCMS::api() in iCMS://app/index/IndexRewrite.php:64 on line 64
5. iCMS::run() in iCMS://core/iCMS.php:167 on line 167
6. Application::run() in iCMS://core/iCMS.php:109 on line 109
7. Application::error() in iCMS://iPHP/Application.php:255 on line 255
8. iPHP::error() in iCMS://iPHP/Application.php:667 on line 667