I hope I can help anyone to get Mamp Pro 5.06 & MySql 8.4+ to work in Windows.

Assuming you have a full working Mamp Pro 5 with MySQL 5.7, first thing to do is make a backup of your MySQL 5.7 database (if needed).

During testing it maybe helpfull to open an Administrator Command window and put this command in it: taskkill /F /IM mysqld.exe in case you have problems replacing files etc.

Before going further it is necessary to close Mamp Pro 5 (stop running services and exit, check the systray).

*** BEFORE GOING FURTHER, IF YOU WANT TO KEEP YOUR DATA BE SURE YOU HAVE MADE A BACKUP ***

STEPS:

1. Download MySQL Community Server 8.4.5 LTS, ZIP Archive (link: https://dev.mysql.com/downloads/file/?id=539262)

2. Unzip it in a download folder and rename it to mysql8

3. Copy all files from your downloaded mysql8 folder to folder C:\MAMP\bin\mysql and replace all files

4. Delete all files in folder C:\MAMP\db\mysql

5. Open my.ini from folder C:\MAMP\conf\mysql

6. In section [mysql] do the following:

Change: character-set-server=utf8 => character-set-server=utf8mb4

Change: collation-server=utf8_general_ci => collation-server=utf8mb4_general_ci

Change: #innodb_flush_log_at_trx_commit = 1 => innodb_flush_log_at_trx_commit = 1

Add: mysql_native_password = ON

7. Save my.ini

8. Open an Administrator Command prompt and goto folder C:\MAMP\bin\mysql\bin

9. Execute: mysqld --initialize --datadir="C:\MAMP\db\mysql" --console

10. In the console you will see a temporary password is generated for root@localhost. Write down or copy this password. (eg. _Ve&xIhG-2CR)

11. Execute: mysqld --defaults-file="C:\MAMP\conf\mysql\my.ini" --console

12. MySQL is now running. Open a new Administrator Command prompt and goto folder C:\MAMP\bin\mysql\bin

13: Excecute: mysql -u root -p (fill in the password from step 10)

14: Excecute: ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'root';

15: Close the database by typing quit <enter> and close the command prompt window

16: Close the command window from step 11.

17: Start MAMP PRO 5 and stop all running services

18: Open template MySQL (my.cnf) via menu File -> Open Template

19: In section [mysql] do the following steps:

Change/check: datadir = MAMP_datadir_MAMP => datadir = C:/MAMP/db/mysql/

Change/check: character-set-server=utf8 => character-set-server=utf8mb4

Change/check: collation-server=utf8_general_ci => collation-server=utf8mb4_general_ci

Change/check: skip-ssl=1 => #skip-ssl=1

Change/check: #innodb_flush_log_at_trx_commit = 1 => innodb_flush_log_at_trx_commit = 1

Add/check: mysql_native_password = ON

20: Save my.ini

21: Start.

Start phpMyAdmin and everything shoud be working fine with MySQL 8.4.

Dismiss the version notice of 5.7.24.

Good luck!

Erik