I am trying to get a CouchCMS site working on a new server having accidentally made the VPS it was running on unbootable. I'm not sure what Couch version it is, but it dates from 2017 [LATER: Updated it to the latest version of Couch and problem still there]. It was running on Ubuntu 12.04 but my new site is Ubuntu 18.04, running nginx 1.14. I have installed php5.6 and have successfully got a simple 'helloworld.php' page working. On CouchCMS pages, though, I'm getting a completely blank page, and a 500 error showing up in the nginx access.log. But I cannot find any details of the error anywhere - it's not in the nginx error.log, nor in php5.6-fpm.log or syslog. So how do I get to see the errors so I know what needs fixing? Does CouchCMS write errors to somewhere else?

Solved in the end. Knowing that the latest version of CouchCMS works with PHP 7, I was able to install PHP 7 on the new server and get it working with nginx OK.