[Error] 
Call to undefined method CChapter::GetList() (0)
/var/www/b14411/data/www/financial-rating.ru/bitrix/components/mag/textbook.tree/component.php:23
#0: include
	/var/www/b14411/data/www/financial-rating.ru/bitrix/modules/main/classes/general/component.php:548
#1: CBitrixComponent->__includeComponent()
	/var/www/b14411/data/www/financial-rating.ru/bitrix/modules/main/classes/general/component.php:600
#2: CBitrixComponent->includeComponent(string, array, boolean)
	/var/www/b14411/data/www/financial-rating.ru/bitrix/modules/main/classes/general/main.php:1035
#3: CAllMain->IncludeComponent(string, string, array, boolean)
	/var/www/b14411/data/www/financial-rating.ru/knowledge-base/textbook/index.php:13