How to find out why php.exe crashes on windows when starting a specific site?

Question

open server

Two out of a bunch of sites running on openserver under windows crash with a 502 error, leaving no clear logs why the crash happened. PHP version 7.1 (changing to 7.0, 7.2 does not change things, as well as changing the version of apache + nginx + mysql to all options available in openserver), changing the computer did not help either =). Site on yii2. The same sites work fine on Linux nginx + php 7.1.
How to debug and catch the cause of the fall of php.exe in the process of "opening" the site?
I don’t even know what else to give information from all the available traces only:

orientir.local: 127.0.0.1 [27/Jul/2018:12:12:39 +0300] "GET / HTTP/1.1" "-" 502 742 "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36" "-"

2018/07/27 12:12:39 [error] 13068#2396: *38 WSARecv() failed (10054: An existing connection was forcibly closed by the remote host) while reading response header from upstream, client: 127.0.0.1, server: orientir.local, request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:8080/", host: "orientir.local"

and in windows application log

Имя сбойного приложения: httpd.exe, версия: 2.4.29.0, метка времени: 0x59fef07b
Имя сбойного модуля: php7ts.dll, версия: 7.1.12.0, метка времени: 0x5a1658eb
Код исключения: 0xc0000005
Смещение ошибки: 0x0000000000021707
Идентификатор сбойного процесса: 0x4e8
Время запуска сбойного приложения: 0x01d42588d68d1472
Путь сбойного приложения: C:\ospanel\modules\http\Apache-PHP-7-x64+Nginx-1.12\bin\httpd.exe
Путь сбойного модуля: c:\ospanel\modules\php\PHP-7.1-x64\php7ts.dll
Идентификатор отчета: 01d25a8d-2cd0-4ed5-aea9-35b0a7ed4d7d
Полное имя сбойного пакета: 
Код приложения, связанного со сбойным пакетом:

Nothing useful came up. Tell me how you can debug, understand the cause of the fall?

Answer 1

solved the problem by replacing 7.1-64 version of php openserver with php-7.1.20-nts-Win32-VC14-x64

Answer 2

are you using pthreads?
try commenting out extension=php_pthreads.dll and run?