If your phpMyAdmin is not working, try the following.
1. Stop your servers and quit MAMP PRO.
Your phpMyAdmin is located in /Library/Application Support/appsolute/MAMP PRO/phpMyAdmin
2. Rename this folder to phpMyAdmin_bak
3. Start MAMP PRO, start your servers
You should have a new /Library/Application Support/appsolute/MAMP PRO/phpMyAdmin