I renamed admin.php, changed config.local.php to reflect the new admin file name, deleted var/cache.
When I try to access the admin page I get these messages.
THIS PAGE ISN'T WORKING
XXXXXXXX. COM sent an INVALID RESPONSE
I checked file permissions and set those according to the documentation. I did use a copy of the original admin.php from before the install instead of just renaming the one on the server.
I don't know what I am missing. Any suggestions are appreciated.
Never mind. I figured it out!
The copy of config.local.php must have been before I had updated everything. Once I supplied the correct information in the section shown below, it started working.
// Host and directory where software is installed on no-secure server
$config['http_host'] = '%HTTP_HOST%';
$config['http_path'] = '%HOST_DIR%';
// Host and directory where software is installed on secure server
$config['https_host'] = '%HTTPS_HOST%';
$config['https_path'] = '%HOST_DIR%';