IIS website displays error 500.
Failed request tracing, configured according to the article shows error, like:
PHP Fatal error: The file C:\Inetpub\vhosts\domain.tld\httpdocs\index.php cannot be decoded by this version of the ionCube Loader. If you are the administrator of this site then please install the latest version of the ionCube Loader. in Unknown on line 0
inonCube Loader version does not support content of website. Higher version is required.
Update ionCube Loader version according to the article