Upgrade from 2.1.4 to 2.1.6 - Permission denied and database errore

[KlausS]

Hi all,

running SMF on a Windows 2019 Server with PHP 7.4. and MySQL 8. Wanted to upgrade to use PHP 8.4

When upgrading from 2.1.4 to 2.1.5 I got some errors, all stating:
Permission denied. I.e.

unlink(E:\HTML\mysite\forum/Packages/temp/UpdateUnicode.php): Permission denied

After the upgrade to 2.1.5 which apparently worked (don't know about the files with permission problem), I tried to upgrade to 2.1.6

There I immediately get a database error and the upgrade is cancelled:

Database Error: Duplicate key name 'id_board'

What could this be?

TIA

Klaus