IIS 7 and Above
Old PHP 5.3.9 FastCGI process exited unexpectedly on typo3
Re: Old PHP 5.3.9 FastCGI process exited unexpectedly on typo3
Jan 09, 2019 03:16 PM|lextm|LINK
It is not an issue with FastCGI module, https://blog.lextudio.com/who-should-be-contacted-for-php-on-iis-issues-c80b90bd365
Nobody would support you if you use PHP 5.3, http://php.net/supported-versions.php and you must use PHP 7.1-7.3, and a suitable version of typo3.