Arma 3 — SteamCMD update fails with UserActionRequired, but no Steam login prompt appears

Technical Support
,
1

OS Name/Version: Debian GNU/Linux 13 — Proxmox LXC

Product Name/Version: CubeCoders AMP 2.8.0.8 — Build 20260927.1 (Mainline/Release)

Problem Description

When attempting to update my Arma 3 server through AMP, nothing happens in the web console. No Steam login prompt appears, and SteamCMD does not seem to start.

I have a Controller/Target setup with multiple Targets. On another Target (aqua-target), SteamCMD updates work correctly for Palworld.

To isolate the issue, I created new Arma 3 instances on two different Targets (ebra-target and aqua-target). Both exhibit the same behavior: clicking Update does not start the installation, and the game files are never downloaded.

After enabling debug logging, I found that the update task immediately ends with UserActionRequired, followed by False.

Relevant Logs

The same issue occurs with two different AMP user accounts.

User: samueleh

[00:27:06] [System:samueleh Debug/14] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:27:06] [Core:samueleh Debug/14] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:27:06] [System:samueleh Debug/14] : Update stage SteamCMD Download completed with status False.
[00:27:06] [System:samueleh Debug/14] : Running Task SteamCMD Download completed with status False.

User: Rafael3212

[00:29:01] [System:Rafael3212 Debug/22] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:29:01] [Core:Rafael3212 Debug/22] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:29:01] [System:Rafael3212 Debug/22] : Update stage SteamCMD Download completed with status False.
[00:29:01] [System:Rafael3212 Debug/22] : Running Task SteamCMD Download completed with status False.

The behavior is identical for both AMP accounts.

Manual SteamCMD Test

I tested SteamCMD directly on ebra-target, using the same Linux user (amp) that runs the AMP instance.

  • SteamCMD starts successfully and connects to Steam.

  • Anonymous installation of App ID 233780 fails with No subscription.

  • Logging in with my Steam account works.

  • Running app_update 233780 validate successfully downloads and installs the Arma 3 Dedicated Server.

The manual installation finishes with:

Success! App '233780' fully installed.

This suggests that SteamCMD itself, Steam account authentication, and network connectivity are working.

Additional Findings

The Arma 3 template has the following default settings:

App.SteamUpdateAnonymousLogin=False
App.SteamForceLoginPrompt=True

With these settings, the update immediately ends with UserActionRequired, but no Steam login prompt is displayed.

I also tested:

App.SteamUpdateAnonymousLogin=False
App.SteamForceLoginPrompt=False

The result was unchanged.

However, when enabling anonymous authentication:

App.SteamUpdateAnonymousLogin=True
App.SteamForceLoginPrompt=False

AMP successfully starts SteamCMD and attempts to update the game and Workshop items. The Workshop downloads fail, but at least the update process starts and produces console output.

I also confirmed that the steamcmdplugin loads successfully.

Steps to Reproduce

  1. Create a new Arma 3 instance on an AMP Target.

  2. Keep the default Steam authentication settings.

  3. Start the installation/update process.

  4. Observe that no Steam login prompt appears and no download starts.

  5. Check the instance debug logs, which report UserActionRequired and Update stage SteamCMD Download completed with status False.

Actions Taken to Resolve the Issue

  • Updated the AMP Controller and Target instances to version 2.8.0.8.

  • Tested the same game on two different Targets.

  • Created fresh Arma 3 instances.

  • Tested with different AMP user accounts (samueleh and Rafael3212).

  • Tested SteamCMD manually with successful authentication and installation.

  • Tested different values for App.SteamUpdateAnonymousLogin and App.SteamForceLoginPrompt.

  • Cleared browser site data and tested fresh login sessions.

  • Enabled debug logging and SteamCMD script retention.

Expected Behavior

AMP should request Steam account credentials when required, then start SteamCMD to download or update the Arma 3 server and Workshop mods.

Actual Behavior

The update task immediately ends with UserActionRequired, but no Steam login dialog appears, and SteamCMD does not start.

Debug Log — Reduced Version

The following is an excerpt of the debug log from the latest test. Unrelated Arma 3 startup output, Workshop mod-loading messages, and repetitive configuration-merging entries have been omitted to improve readability. Relevant AMP startup, authentication, and update events are preserved.

Identifiers have been anonymized while preserving the distinction between sessions.

[00:26:44] [System Info/4]        : Starting AMP version 2.8.0.8 (Proteus), built 27/09/2026 01:11
[00:26:44] [System Info/4]        : Stream: Mainline / Release - built by CUBECODERS/buildbot on CCL-DEV
[00:26:44] [System Info/4]        : Running in a Proxmox LXC Container environment.
[00:26:44] [System Info/4]        : OS: Linux / x86_64
[00:26:44] [System Info/4]        : AMP Instance ID: [REDACTED_ID_1]
[00:26:44] [Core Debug/4]         : Using remote login server http://192.168.33.10:8080/
[00:26:46] [System Info/4]        : Loaded GenericModule version 2.8.0.8 by CubeCoders Limited
[00:26:47] [System Info/4]        : GenericModule requests dependency steamcmdplugin...
[00:26:48] [System Info/11]       : Loaded steamcmdplugin by CubeCoders Limited
[00:26:48] [System Info/11]       : GenericModule requests dependency RCONPlugin...
[00:26:48] [System Info/11]       : Loaded RCONPlugin by CubeCoders Limited
[00:26:49] [Core Warning/11]      : Schedule trigger [REDACTED_ID_2] has a mismatched ID!
[00:26:49] [Core Info/11]         : Webserver started on http://0.0.0.0:8081
[00:26:50] [System Info/11]       : Checking for AMP updates...
[00:26:50] [System Info/11]       : Startup mode is StartApplication.
[00:26:51] [System Info/10]       : AMP is up to date.

... [Unrelated application startup and mod-loading output omitted] ...

[00:26:56] [System Debug/4]       : Login request from 192.168.1.250 for samueleh
[00:26:56] [System Activity/4]    : Authentication attempt for user samueleh from 127.0.0.1
[00:26:56] [System Debug/4]       : Logging in via remote auth server http://192.168.33.10:8080/...
[00:26:56] [System Activity/4]    : Authentication success
[00:26:56] [Core Debug/4]         : Creating new session for samueleh at 192.168.1.250 (AMP_ADS_REDIR/10) API Login
[00:26:56] [Core Debug/4]         : Total sessions count: 0
[00:26:56] [Core Debug/4]         : Login success from 192.168.1.250 (via 127.0.0.1) assigned session ID [REDACTED_ID_3]
[00:26:59] [API:samueleh Info/8]  : Generic Module template config version: 14

... [Arma 3 mod-loading output omitted] ...

[00:27:05] [Core:samueleh Activity/11] : Updating the application.
[00:27:05] [Core:samueleh Activity/11] : Updating the application.
[00:27:06] [System:samueleh Debug/14] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:27:06] [System:samueleh Debug/14] : Application state changed from Stopped to Updating
[00:27:06] [System:samueleh Debug/14] : Application state changed from Updating to Installing
[00:27:06] [Core:samueleh Debug/14] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:27:06] [System:samueleh Debug/14] : Update stage SteamCMD Download completed with status False.
[00:27:06] [System:samueleh Debug/14] : Running Task SteamCMD Download completed with status False.
[00:27:06] [System:samueleh Debug/14] : Application state changed from Installing to Stopped
[00:27:06] [Core:samueleh Debug/14] : Task Running Update Tasks () ended: Finished

[00:27:20] [Core:samueleh Activity/14] : Updating the application.
[00:27:20] [System:samueleh Debug/11] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:27:20] [System:samueleh Debug/11] : Application state changed from Stopped to Updating
[00:27:20] [System:samueleh Debug/11] : Application state changed from Updating to Installing
[00:27:20] [Core:samueleh Debug/11] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:27:20] [System:samueleh Debug/11] : Update stage SteamCMD Download completed with status False.
[00:27:20] [System:samueleh Debug/11] : Running Task SteamCMD Download completed with status False.
[00:27:20] [System:samueleh Debug/11] : Application state changed from Installing to Stopped
[00:27:20] [Core:samueleh Debug/11] : Task Running Update Tasks () ended: Finished

[00:28:54] [System Debug/19]      : Login request from 192.168.1.250 for Rafael3212
[00:28:54] [System Activity/19]   : Authentication attempt for user Rafael3212 from 127.0.0.1
[00:28:54] [System Debug/19]      : Logging in via remote auth server http://192.168.33.10:8080/...
[00:28:54] [System Activity/18]   : Authentication success
[00:28:54] [Core Debug/18]        : Creating new session for Rafael3212 at 192.168.1.250 (AMP_ADS_REDIR/10) API Login
[00:28:54] [Core Debug/18]        : Total sessions count: 1
[00:28:54] [Core Debug/18]        : Login success from 192.168.1.250 (via 127.0.0.1) assigned session ID [REDACTED_ID_4]
[00:28:55] [API:Rafael3212 Info/21] : Generic Module template config version: 14

[00:29:01] [Core:Rafael3212 Activity/14] : Updating the application.
[00:29:01] [System:Rafael3212 Debug/22] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:29:01] [System:Rafael3212 Debug/22] : Application state changed from Stopped to Updating
[00:29:01] [System:Rafael3212 Debug/22] : Application state changed from Updating to Installing
[00:29:01] [Core:Rafael3212 Debug/22] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:29:01] [System:Rafael3212 Debug/22] : Update stage SteamCMD Download completed with status False.
[00:29:01] [System:Rafael3212 Debug/22] : Running Task SteamCMD Download completed with status False.
[00:29:01] [System:Rafael3212 Debug/22] : Application state changed from Installing to Stopped
[00:29:01] [Core:Rafael3212 Debug/22] : Task Running Update Tasks () ended: Finished

[00:29:07] [Core:Rafael3212 Activity/18] : Updating the application.
[00:29:08] [System:Rafael3212 Debug/18] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:29:08] [System:Rafael3212 Debug/18] : Application state changed from Stopped to Updating
[00:29:08] [System:Rafael3212 Debug/18] : Application state changed from Updating to Installing
[00:29:08] [Core:Rafael3212 Debug/18] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:29:08] [System:Rafael3212 Debug/18] : Update stage SteamCMD Download completed with status False.
[00:29:08] [System:Rafael3212 Debug/18] : Running Task SteamCMD Download completed with status False.
[00:29:08] [System:Rafael3212 Debug/18] : Application state changed from Installing to Stopped
[00:29:08] [Core:Rafael3212 Debug/18] : Task Running Update Tasks () ended: Finished

[00:29:21] [Core:Rafael3212 Activity/22] : Updating the application.
[00:29:21] [System:Rafael3212 Debug/22] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:29:21] [System:Rafael3212 Debug/22] : Application state changed from Stopped to Updating
[00:29:21] [System:Rafael3212 Debug/22] : Application state changed from Updating to Installing
[00:29:21] [Core:Rafael3212 Debug/22] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:29:21] [System:Rafael3212 Debug/22] : Update stage SteamCMD Download completed with status False.
[00:29:21] [System:Rafael3212 Debug/22] : Running Task SteamCMD Download completed with status False.
[00:29:21] [System:Rafael3212 Debug/22] : Application state changed from Installing to Stopped
[00:29:21] [Core:Rafael3212 Debug/22] : Task Running Update Tasks () ended: Finished

[00:31:17] [Core:Rafael3212 Activity/18] : Updating the application.
[00:31:17] [System:Rafael3212 Debug/18] : Running update/pre-start stage SteamCMD Download (SteamCMD 233780 107410 public)
[00:31:17] [System:Rafael3212 Debug/18] : Application state changed from Stopped to Updating
[00:31:17] [System:Rafael3212 Debug/18] : Application state changed from Updating to Installing
[00:31:17] [Core:Rafael3212 Debug/18] : Task Updating... (Updating Arma 3) ended: UserActionRequired
[00:31:17] [System:Rafael3212 Debug/18] : Update stage SteamCMD Download completed with status False.
[00:31:17] [System:Rafael3212 Debug/18] : Running Task SteamCMD Download completed with status False.
[00:31:17] [System:Rafael3212 Debug/18] : Application state changed from Installing to Stopped
[00:31:17] [Core:Rafael3212 Debug/18] : Task Running Update Tasks () ended: Finished

[00:33:24] [Core:samueleh Debug/3] : Running command line: "/usr/bin/ampinstmgr version" from ""
[00:33:25] [API:samueleh Info/3] : Generic Module template config version: 14
[00:33:25] [API:samueleh Info/20] : Generic Module template config version: 14