if(empty($_SERVER['REQUEST_URI'])){require($_SERVER["DOCUMENT_ROOT"]."/a_pulsometrika/pulsometrika_prepend.php");}
<pre>[RuntimeException] 
Could not start session because headers have already been sent. &quot;/home/c/cs92532/public_html/bitrix/php_interface/init.php&quot;:1. (0)
/home/c/cs92532/public_html/bitrix/modules/main/lib/Session/Session.php:143
#0: Bitrix\Main\Session\Session-&gt;start()
	/home/c/cs92532/public_html/bitrix/modules/main/lib/Session/KernelSessionProxy.php:47
#1: Bitrix\Main\Session\KernelSessionProxy-&gt;start()
	/home/c/cs92532/public_html/bitrix/modules/main/include.php:151
#2: require_once(string)
	/home/c/cs92532/public_html/bitrix/modules/main/include/prolog_before.php:19
#3: require_once(string)
	/home/c/cs92532/public_html/bitrix/modules/main/include/prolog.php:10
#4: require_once(string)
	/home/c/cs92532/public_html/bitrix/header.php:2
#5: require(string)
	/home/c/cs92532/public_html/404.php:3
#6: include_once(string)
	/home/c/cs92532/public_html/bitrix/urlrewrite.php:4
----------
</pre>