Installation Error with Nextcloud 15 on Ubuntu 18.04/Apache2

I attempted to install Nextcloud 15 on Ubuntu 18.04 running Apache2, MySQL, and PHP 7.2. This is a functional server that already has a dozen PHP sites that work correctly so the site-wide Apache and PHP environment is configured correctly. I also confirmed that www-data owns the entire folder and contents.

When trying to reach the Nextcloud installation page, even when manually typing /index.php as the URL, the browser displays the raw HTML for the installation page (I can see a bunch of script tags referring to installation files). Oddly, when I inspect the page, it appears as visible HTML wrapped inside >pre< tags which are inside another HTML page.

The apache error log and the site-specific virtual host log are empty.

Things I’ve tried:

  • I added a “data” folder in the siteroot before trying the installation again. A nextcloud.log file is created in this folder but it’s empty.

  • Deleting the config/config.php file created during the aborted installation process and trying again. The only thing that ever appears in this file is a $CONFIG array containing an “instanceid” key.

I would assume some sort of PHP or Apache error, but again, we already run a dozen Drupal and Wordpress sites in this environment with no problems whatsoever.

Any suggestions? Many thanks!