Case:
1) Add rpoduct to cart
2) Click to Checkout button
3) Internal Error. Details are available in Magento log file. Report ID: webapi-56b2093cb657a
[2016-02-03 14:05:48] main.CRITICAL: exception 'Exception' with message 'Report ID: webapi-56b2093cb657a; Message: Notice: Undefined index: Magento\CatalogRule\Plugin\Indexer\Product\Save\ApplyRulesAfterReindex in /home/public_html/magento2/vendor/magento/framework/Interception/Definition/Compiled.php on line 37' in /home/public_html/magento2/vendor/magento/framework/Webapi/ErrorProcessor.php:194
Stack trace:
#0 /home/public_html/magento2/vendor/magento/framework/Webapi/ErrorProcessor.php(139): Magento\Framework\Webapi\ErrorProcessor->_critical(Object(Exception))
#1 /home/public_html/magento2/vendor/magento/module-webapi/Controller/Rest.php(163): Magento\Framework\Webapi\ErrorProcessor->maskException(Object(Exception))
#2 /home/public_html/magento2/var/generation/Magento/Webapi/Controller/Rest/Interceptor.php(24): Magento\Webapi\Controller\Rest->dispatch(Object(Magento\Framework\App\Request\Http))
#3 /home/public_html/magento2/vendor/magento/framework/App/Http.php(115): Magento\Webapi\Controller\Rest\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#4 /home/public_html/magento2/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
#5 /home/public_html/magento2/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))
#6 {main} [] []
What is the cause and how to fix it?
Best,
Boris