Can't log in to old site "license key isn't valid for this domain"

Hi,

I'm working on a client's old Perch site. I can log in fine to the live site's admin but I can't log in to a local version of the same site (I created a fresh copy from the live site).

I have access to the Perch account where the license is and updated the Development domain appropriately, and triple-checked that it is the correct license number and have tried a couple of different domains in case there was some format issue.

Can't think of what else to do to get access to Perch from a new domain. I'm using MAMP and can set the domain to whatever I want, if that helps.

Diagnostics:

Perch: 2.8.6, PHP: 7.0.32, MySQL: mysqlnd 5.0.12-dev - 20150407 - $Id: b5c5906d452ec590732a93b051f3827e02749b83 $, with PDO
Server OS: Linux, cgi-fcgi
Installed apps: content (2.8.6), assets (2.8.6), categories (2.8.6)
App runtimes: <?php include(PERCH_PATH.'/core/apps/content/runtime.php'); include(PERCH_PATH.'/addons/apps/kirk_meta/runtime.php'); include(PERCH_PATH.'/addons/apps/kirk_admin_links/runtime.php'); include(PERCH_PATH.'/addons/apps/kirk_email_obfuscator/runtime.php'); ?>
PERCH_LOGINPATH: /admin
PERCH_PATH: /home/pbnhccom/public_html/plantricianproject.org/admin
PERCH_CORE: /home/pbnhccom/public_html/plantricianproject.org/admin/core
PERCH_RESFILEPATH: /home/pbnhccom/public_html/plantricianproject.org/admin/resources
Image manipulation: GD
PHP limits: Max upload 100M, Max POST 8M, Memory: 512M, Total max file upload: 8M
Resource folder writeable: Yes
DOCUMENT_ROOT: /home/pbnhccom/public_html/plantricianproject.org
HTTP_HOST: plantricianproject.org
REQUEST_URI: /admin/core/settings/diagnostics/
SCRIPT_NAME: /admin/core/settings/diagnostics/index.php