Not Found
The requested URL /magento2/admin_cgcu4j/ was not found on this server.
Not Found
The requested URL /magento2/admin_cgcu4j/admin/index/index/key/4c241c03f41c5d9d48d4c8dc0c8d2dff3447f861fb908f15a1ad0d72330f24f5/ was not found on this server.
Any other suggestions would be greatly appreciated!
Hmm. Is MySQL the right version in MAMP these days? I assume so if you got through the installer.
I assume /admin_cgcu4j is what the installer gave you, not cached from a previous session. A different URL is generated per run as a security feature. So just making sure the current install URL and not a previous run.
Does index.php work on the site or any other URLs? If so, that would indicate this is not the right admin URL.
Hmm, I have the same problem with a clean 2.1.2 installation
I was never able to find the root cause as my company moved to a web-based host (https://www.crucialhosting.com) where I used their tools to install Magento 2.1.2 and have had no issues.
Good luck!