[Error] 
Class 'CProductQueryBuilder' not found (0)
/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:1873
#0: Bitrix\Iblock\Component\Base->convertSelect(array)
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:1766
#1: Bitrix\Iblock\Component\Base->prepareQueryFields(array, array, array)
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:1742
#2: Bitrix\Iblock\Component\Base->prepareElementQueryFields()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:1673
#3: Bitrix\Iblock\Component\Base->initQueryFields()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:768
#4: Bitrix\Iblock\Component\Base->initElementList()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:3950
#5: Bitrix\Iblock\Component\Base->processResultData()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/element.php:286
#6: Bitrix\Iblock\Component\Element->processResultData()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:4453
#7: Bitrix\Iblock\Component\Base->loadData()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:4442
#8: Bitrix\Iblock\Component\Base->initialLoadAction()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/element.php:271
#9: Bitrix\Iblock\Component\Element->initialLoadAction()
	
#10: call_user_func(array)
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:4627
#11: Bitrix\Iblock\Component\Base->doAction()
	/home/c/cb52567/public_html/bitrix/modules/iblock/lib/component/base.php:4645
#12: Bitrix\Iblock\Component\Base->executeComponent()
	/home/c/cb52567/public_html/bitrix/modules/main/classes/general/component.php:648
#13: CBitrixComponent->includeComponent(string, array, boolean)
	/home/c/cb52567/public_html/bitrix/modules/main/classes/general/main.php:1039
#14: CAllMain->IncludeComponent(string, string, array, boolean)
	/home/c/cb52567/public_html/books/item.php:148
#15: include_once(string)
	/home/c/cb52567/public_html/bitrix/modules/main/include/urlrewrite.php:159
#16: include_once(string)
	/home/c/cb52567/public_html/bitrix/urlrewrite.php:2