[Error] 
Undefined constant "IS_MAIN" (0)
/home/bitrix/ext_www/eng.smartpress.by/local/templates/eng/header.php:173
#0: include_once
	/home/bitrix/ext_www/smartpress.by/bitrix/modules/main/include/prolog_after.php:120
#1: require(string)
	/home/bitrix/ext_www/smartpress.by/bitrix/modules/main/include/prolog.php:11
#2: require_once(string)
	/home/bitrix/ext_www/smartpress.by/bitrix/header.php:1
#3: require(string)
	/home/bitrix/ext_www/eng.smartpress.by/index.php:2
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