install.php gives 500 error

I am doing a fresh install (new virtual server) on DigitalOcean FreeBSD 11.1.
I have followed the instructions at https://www.digitalocean.com/community/tutorials/how-to-install-an-apache-mysql-and-php-famp-stack-on-freebsd-10-1 to install the FAMP stack without issues.
I then followed the instructions at https://www.digitalocean.com/community/tutorials/how-to-install-wordpress-with-apache-on-freebsd-10-1 to install WordPress. Everything works fine until I try to run the installation. When I go to the base URL, it redirects to wp-admin/install.php and gives me a 500 error. Running a script with php_phpinfo() works fine, and running a script with mysql_connect() also works without issues (same credentials as wp-config.php). I generated authentication keys and put them in the config file as well.
I tried to use main/repair.php, but all that does is spit out errors saying all the DB tables are missing.
I would appreciate any help on resolving this.

Thanks,
Marc.