Ok, the error according to the log file is
CAQuietExec64: Running bootstrap
CAQuietExec64: Registering service 'MariaDB'
CAQuietExec64: FATAL ERROR: Can't write to ini file key=datadir, val=C:/Program Files/MariaDB 11.4/data, section=mysqld, Windows error 5
CAQuietExec64: Creating my.ini file
I think we have never seen anything like that . Error 5 is ERROR_ACCESS_DENIED
I can imagine it happens if some 3rd party antivirus holds the file open, without sufficient sharing. Might this also apply in this case? Can you try to disable whatever antivirus runs on the box for the time of installation
There is also something that MariaDB can do, as it defensively tries to anticipate buggy antivirus elsewhere in the code, with retry logic during file open/move/delete.
Jelkelueschen, to analyze such kind of errors, MSI log is necessary.
Generic instructions are these :
start MSI from the elevated command line, as
msiexec /i Example.msi /quiet /L*v "C:\tmp\mariadb-install-log.txt"
Replace Example.msi with the real MSI name, and make sure C:\tmp exists.
After that, please attach mariadb-install-log.txt to the ticket.