This is my problem:
https://caddy.community/t/nextcloud-php-errors/3653/3?u=xincun
I found caddy unable to start php-cgi.exe. Inspired by the upper floors, I testing 2 version the same (10.10&10.12) on win7x64.
caddy10.10 and php7.2.4:
When caddy starts, php-cgi.exe starts at the same time. Everything is OK.
caddy10.12 and php7.2.4:
When caddy starts, php-cgi.exe does not running.
The same environment, the same config.