NextCloud 11 missing config file exception

I am doing a manual install of Nextcloud 11.03 on a Fedora 25 Server. I am doing this to get the latest version of Nextcloud, and to learn more about Nextcloud admin.

On a different server, I successfully installed Nextcloud version 10 using the Fedora repos, so I know it works on a Fedora 25 Server.

When I do a manual install, I get the following error messages in /var/log/httpd/ssl_error_log

PHP Warning:  flock() expects parameter 1 to be resource, 
boolean given in /var/www/nextcloud/lib/private/Config.php on line 198

PHP Fatal error:  Uncaught Error: Call to a member function getLogger()
 on null in /var/www/nextcloud/index.php:55
\nStack trace:\n#0 {main}\n
thrown in /var/www/nextcloud/index.php on line 55

The flock() warning refers to this piece of code in /var/www/nextcloud/lib/private/Config.php:

// Try to acquire a file lock
  if(!flock($filePointer, LOCK_SH)) {
     throw new \Exception(sprintf('Could not acquire a shared lock on the config file %s', $file));

This error message does not show up in any of the log files, so I cannot tell which config file it is refering to.

I compared the Fedora 25 repo installation with my manual installation and as far as I can tell, all config files are present.

Can anyone tell me how to find out which config file it it looking for?