The installed Steam client might be old. Steam stopped supporting Windows 7 in 2024.
The tail of the launcher.log file shows:
```
2025-06-29 10:41:25,289 [ INFO] 1: LauncherViewModel: Arma 3 path: D:\SteamLibrary\steamapps\common\Arma 3
2025-06-29 10:41:27,311 [ INFO] 1: LauncherViewModel: View loaded, commencing initialization tasks...
2025-06-29 10:41:27,330 [ INFO] 1: LauncherViewModel: Initializing module News
2025-06-29 10:41:28,239 [ INFO] 1: LauncherViewModel: Initializing module Units
2025-06-29 10:41:28,239 [ INFO] 1: LauncherViewModel: Initializing module Game executor and monitor
2025-06-29 10:41:28,240 [ INFO] 1: LauncherViewModel: Initializing module Game profiles
2025-06-29 10:41:28,383 [ INFO] 1: LauncherViewModel: Initialized Game profiles
2025-06-29 10:41:28,383 [ INFO] 1: LauncherViewModel: Constructing extension management...
2025-06-29 10:41:29,333 [ INFO] 1: SteamExtensionStorage: Hooked to facade.
2025-06-29 10:41:29,347 [ INFO] 1: LauncherViewModel: Initializing extension management.
2025-06-29 10:41:29,348 [ INFO] 1: LauncherViewModel: Initializing module PBO registry
2025-06-29 10:41:29,349 [ INFO] 1: LauncherViewModel: Initializing module BISIGN registry
2025-06-29 10:41:29,349 [ INFO] 1: LauncherViewModel: Initializing module UGC manager
2025-06-29 10:41:29,709 [ INFO] 1: LauncherViewModel: Initialized PBO registry
2025-06-29 10:41:29,709 [ INFO] 1: LauncherViewModel: Initialized BISIGN registry
2025-06-29 10:41:29,709 [ INFO] 1: LauncherViewModel: Initialized UGC manager
2025-06-29 10:41:29,717 [ INFO] 1: LauncherViewModel: Initializing dlc managers
2025-06-29 10:41:29,754 [ INFO] 5: Launcher.Dlc.DlcManager: Store Storage preloaded
2025-06-29 10:41:29,763 [ INFO] 1: LauncherViewModel: Initialized Game executor and monitor
2025-06-29 10:41:29,763 [ INFO] 1: LauncherViewModel: Initialized Units
2025-06-29 10:41:29,795 [ INFO] 1: LauncherViewModel: Initializing addon managers
2025-06-29 10:41:29,931 [ INFO] 5: SteamExtensionStorageSerializer: Preloading Steam extensions:
2025-06-29 10:41:29,931 [ INFO] 5: Launcher.Extensions.ExtensionManager: Store Steam preloaded
2025-06-29 10:41:34,478 [ INFO] 4: Launcher.Extensions.ExtensionManager: Store Local preloaded
2025-06-29 10:41:34,478 [ INFO] 1: LauncherViewModel: Initializing preset managers
2025-06-29 10:41:34,555 [ INFO] 1: LauncherViewModel: Preset initialized
2025-06-29 10:41:34,588 [ INFO] 12: Launcher.Dlc.DlcManager: End compose
2025-06-29 10:41:34,602 [ INFO] 1: ExtensionManagementViewModel: RefreshExtensionsView
2025-06-29 10:41:34,610 [ INFO] 5: SteamUgcDownloadManager: Steam UGC Download manager initialization 0
2025-06-29 10:41:34,610 [ INFO] 5: SteamExtensionStorage: Wait for content list changed...
2025-06-29 10:41:34,650 [ INFO] 15: Launcher.Extensions.ExtensionManager: End compose
2025-06-29 10:41:34,655 [ INFO] 1: LauncherViewModel: - Initializing connection to Steam client...
2025-06-29 10:41:34,679 [ INFO] 1: LauncherViewModel: Initialized News
2025-06-29 10:41:34,723 [ INFO] 1: ExtensionManagementViewModel: RefreshExtensionsView
2025-06-29 10:41:34,745 [ERROR] 5: SteamLayer: d:\Bis\Source\Stable\Futura\El\Interfaces\iEval.hpp(38) : Assertion failed 'n == 0'
2025-06-29 10:41:34,765 [ INFO] 5: Steam.Wrap: SteamAPIWrap::Init
2025-06-29 10:41:34,844 [ERROR] 5: SteamLayer: SteamAPI_Init failed. Unable to initialize SteamWorksSDK.
2025-06-29 10:41:34,845 [ INFO] 5: Launcher.Steam.LauncherSteamFacade: Steam init result: APIInitFailed
2025-06-29 10:41:34,959 [ INFO] 5: Stats: Initializing statistics facade.
2025-06-29 10:41:34,974 [ INFO] 5: SteamDlcManager: Steam is offline
```
The Server.Browser.Service.log doesn't show anything for the session.
A fragment of the Steam.Native.log file showing the last successful server fetch in April (using v2.19 launcher) and the failed one today:
```
[BEGIN LOGGING AT 2025-04-20 22:58:12,783]
2025-04-20 22:58:22,036 [ERROR] 5 SteamLayer: d:\Bis\Source\Stable\Futura\El\Interfaces\iEval.hpp(38) : Assertion failed 'n == 0'
[BEGIN LOGGING AT 2025-06-29 00:50:11,932]
2025-06-29 00:50:20,994 [ERROR] 13 SteamLayer: d:\Bis\Source\Stable\Futura\El\Interfaces\iEval.hpp(38) : Assertion failed 'n == 0'
2025-06-29 00:50:21,112 [ERROR] 13 SteamLayer: SteamAPI_Init failed. Unable to initialize SteamWorksSDK.
```
The game log (.rpt) shows multiple messages like this:
```
10:46:07 Unable to initialize Steam API.
10:42:09 SteamAPI initialization failed. Steam features won't be accessible!
```