Attempting to install causes my webserver to throw 500

Using apache2, virtualhost file is:

    <VirtualHost *>
      # Change this to the domain which points to your host.
      ServerName phabricator.redstonedesigner.com

      # Change this to the path where you put 'phabricator' when you checked it
      # out from GitHub when following the Installation Guide.
      #
      # Make sure you include "/webroot" at the end!
      DocumentRoot /var/www/phabricator/phabricator/webroot

      RewriteEngine on
      RewriteRule ^(.*)$          /index.php?__path__=$1  [B,L,QSA]
      <Directory "/var/www/phabricator/phabricator/webroot">
        Require all granted
      </Directory>
    </VirtualHost>

Domain: phabricator.redstonedesigner.com
I have followed the installation guide.

Have you tried looking into the server’s error log?

[Sat Jan 18 11:36:48.340442 2020] [mpm_prefork:notice] [pid 8411] AH00163: Apache/2.4.38 (Debian) configured – resuming normal operations
[Sat Jan 18 11:36:48.340467 2020] [core:notice] [pid 8411] AH00094: Command line: ‘/usr/sbin/apache2’

Those are the only lines after my most recent restart.

I have rectified the issue.
When creating the VirtualHost, the opening line needs to have your domain name instead of the asterisk.

When creating the VirtualHost, the opening line needs to have your domain name instead of the asterisk.

Note that this is not true universally; my local install and all our production hosts use <VirtualHost *>, and the installation instructions work properly in the general case. You may have other configuration which is in conflict with this.