==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.7
- Linux/BSD distribution name and version:  Ubuntu 18
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I just upgraded my server to the latest version of Ubuntu 18.  After a number of choices the upgrade finished.  But the iRedMail splash screen does not appear.  I see nothing but text from a JavaScript file.  Essentially gibberish. 

Luckily, the underlying engine is untouched.  I am able to SSH into the instance.

Can this be fixed?  Is there one simple switch or config file that was bypassed?

Here's just a portion of what I see:
| | Author: Aleksander Machniak | +-------------------------------------------------------------------------+ */ // include environment require_once 'program/include/iniset.php'; // init application, start session, init output class, etc. $RCMAIL = rcmail::get_instance(0, $GLOBALS['env']); // Make the whole PHP output non-cacheable (#1487797) $RCMAIL->output->nocacheing_headers(); $RCMAIL->output->common_headers(); // turn on output buffering ob_start(); // check if config files had errors if ($err_str = $RCMAIL->config->get_error()) { rcmail::raise_error(array( 'code' => 601, 'type' => 'php', 'message' => $err_str), false, true); } // check DB connections and exit on failure if ($err_str = $RCMAIL->db->is_error()) { rcmail::raise_error(array( 'code' => 603, 'type' => 'db', 'message' => $err_str), false, true); } // error steps if ($RCMAIL->action == 'error' && !empty($_GET['_code'])) { rcmail::raise_error(array('code' => hexdec($_GET['_code'])), false, true); } // check if https is required (for login) and redirect if necessary if (empty($_SESSION['user_id']) && ($force_https = $RCMAIL->config->get('force_https', false))) { // force_https can be true, , :, if (!is_bool($force_https)) { list($host, $port) = explode(':', $force_https); if (is_numeric($host) && empty($port)) { $port = $host; $host = ''; } } if (!rcube_utils::https_check($port ?: 443)) { if (empty($host)) { $host = preg_replace('/:[0-9]+$/', '', $_SERVER['HTTP_HOST']); } if ($port && $port != 443) { $host .=