site or steam, guessing you mean site version, so i reply with that in mind.
install and run the game from a admin account and play and update with run as admin as well,
when it comes to use the inbuilt updating tool, run as admin lets the game grab the correct version for you automatically and allows the program to have the correct file permissions for firewall and anti virus etc.
using your mypage button on the forum will also let you manually download the correct setup versions to install without using the auto updater, either way good luck and hope that sort it for you
Name Version Date
[PC] Installer v1.01.01
HeadQuarters-WorldWarII-SetupRelease-v1.00.01.zip 1.01.01 Oct 04, 2024
PC Installer for Headquarters: World War II v1.01.01
[PC] Update v1.04.01 May 14, 2025
so base game installer version base game ver 1.00.01? maybe no longer supported, but auto updater should fix that issue as well, if not that's a support email you will need to send
support@slitherine.co.uk