download mariadb-10.4.12-win32.zip

unzip into e:\wamp\bin\mariadb\
It is :
e:\wamp\bin\mariadb\mariadb-10.4.12-win32\
renamed into :
e:\wamp\bin\mariadb\mariadb10.4.12\
Create mysql database by :
Nota : command windows is "administrator"
cd /d j:\wamp\bin\mariadb\mariadb10.4.12\bin
E:\wamp\bin\mariadb\mariadb10.4.12\bin>mysql_install_db.exe --default-user --datadir=j:\wamp\bin\mariadb\mariadb10.4.12\data
Running bootstrap
2020-01-30 10:07:33 0 [Note] E:\wamp\bin\mariadb\mariadb10.4.12\bin\mysqld.exe (mysqld 10.4.12-MariaDB) starting as process 8384 ...
Creating my.ini file
Creation of the database was successful

E:\wamp\bin\mariadb\mariadb10.4.12\data\my.ini file deleted and replaced by
E:\wamp\bin\mariadb\mariadb10.4.12\my.ini

Create service with :
E:\wamp\bin\mariadb\mariadb10.4.12\bin>mysqld.exe --install-manual wampmariadb
Service successfully installed.

E:\wamp\bin\mariadb\mariadb10.4.12\bin>

Start service with :
E:\wamp\bin\mariadb\mariadb10.4.12\bin>net start wampmariadb
Le service wampmariadb démarre...
Le service wampmariadb n’a pas pu être lancé.
Une erreur système s’est produite.
L’erreur système 1067 s’est produite.
Le processus s’est arrêté inopinément.
Note: Translation into English
The wampmariadb service starts...
The wampmariadb service could not start.
A system error occurred.
System error 1067 occurred.
The process stopped unexpectedly.

In the event viewer there are:
wampmariadb (mysqld 10.4.12-MariaDB) starting as process 13092 ...
aborting

No more information.

Exactly the same problem for versions 10.2.31, 10.3.22, 10.4.12 in 32 and 64 bit.
The installation procedures are exactly the same as for versions 10.2.30, 10.3.21 and 10.4.11, which pose no problem.

For your information, same problem with the latest alpha 10.5.0 versions, whereas it worked perfectly with the previous versions.