Trying to install 8.0.2 but get "Cannot load DB manager"


I am desperately trying to get a 8.0.2 server up and running in EC2.

I get to the DB page and upon clicking "Next" I get at the top:

display_stack_trace caller, file: /var/www/sugar/include/database/DBManagerFactory.php line#: 48
Cannot load DB manager

Amazon EC2 c5,large

Ubuntu 16.04

php 7.1

percona mysql 5.7

I have confirmed php has no issues talking with mysql with a test file that has:

$conn = mysqli_connect($servername, $username, $password);

I have tried using different version combos: 7.0 with 5.6, 71. with 5.6, etc. to no avail.

Can anyone please point me in any direction?