We have MariaDB x64 10.0.19 running on Windows Server R2. I ran the MardiaDB 10.3.14 install. I chose the "upgrade" option, defaults everywhere, and the install went fine, except the final upgrade tool threw an exception. If I go to "c:\program files\mariadb 10.3\bin" and run "mysql_upgrade_service --service=MySQL, then it throws an exception on phase 3/10, ensuring innodb slow shutdown.
Attached is a minidump crash report.