Client crashes on connect when `sv_enforceGameBuild 3751` is enabled on Linux/Docker FXServer

[unknown-urge]

What happened?

I can connect successfully to a vanilla Linux FXServer running in Docker, but my FiveM client crashes when connecting to a Linux/Docker server that enables:

sv_enforceGameBuild 3751

I bisected this down to the enforced game build setting itself. The same server setup does not crash when that line is removed.

Environment

• Host OS: Windows
• Server runtime: FXServer on Linux in Docker
• Reproduced with:
  • spritsail/fivem:latest
  • custom Docker image using FiveM Linux artifact
• Also reproduced with an empty resource, so this does not appear to depend on my resource code

What happens

• Server starts normally
• info.json is reachable
• Client gets to Connecting to server
• FiveM client crashes during/after connect when sv_enforceGameBuild 3751 is enabled

When I remove sv_enforceGameBuild 3751, the same Docker/Linux server can be joined successfully.

Expected result

If the server is reachable and otherwise valid, enabling: cfg sv_enforceGameBuild 3751 should not crash the client.

Reproduction steps

1. Start a completely vanilla server in Docker

This works.

docker run --name spritsail-fivem-vanilla -p 30122:30120/tcp -p 30122:30120/udp -e LICENSE_KEY=<redacted> -itd spritsail/fivem

This vanilla server responds on:

http://127.0.0.1:30122/info.json

and can be joined without crashing.

2. Start a minimal custom-config server with an empty resource

I created a minimal empty resource:

fx_version 'cerulean'
game 'gta5'

3. Test configs

Working baseline

This does not crash:

endpoint_add_tcp "0.0.0.0:30120"
endpoint_add_udp "0.0.0.0:30120"

ensure emptytest

sv_scriptHookAllowed 0
sv_hostname "Project - Compat Empty Test"
sv_endpointprivacy true
sv_maxclients 32
sv_licenseKey <redacted>
set steam_webApiKey ""

Test: only sv_maxclients 48

This does not crash:

endpoint_add_tcp "0.0.0.0:30120"
endpoint_add_udp "0.0.0.0:30120"

ensure emptytest

sv_scriptHookAllowed 0
sv_hostname "Project - Test MaxClients"
sv_endpointprivacy true
sv_maxclients 48
sv_licenseKey <redacted>
set steam_webApiKey ""

Test: only sv_enforceGameBuild 3751

This does crash:

endpoint_add_tcp "0.0.0.0:30120"
endpoint_add_udp "0.0.0.0:30120"

ensure emptytest

sv_scriptHookAllowed 0
sv_hostname "Project - Test Build"
sv_endpointprivacy true
sv_maxclients 32
sv_enforceGameBuild 3751
sv_licenseKey <redacted>
set steam_webApiKey ""

Test: sv_enforceGameBuild 3751 + sv_maxclients 48

This also crashes:

endpoint_add_tcp "0.0.0.0:30120"
endpoint_add_udp "0.0.0.0:30120"

ensure emptytest

sv_scriptHookAllowed 0
sv_hostname "Project - Test Build And MaxClients"
sv_endpointprivacy true
sv_maxclients 48
sv_enforceGameBuild 3751
sv_licenseKey <redacted>
set steam_webApiKey ""

Importancy

Crash

Area(s)

FXServer, FiveM

Specific version(s)

FXServer-master v1.0.0.30707 linux

Additional information

No response

[yorick2002]

I tested this with a very fresh txAdmin server with Cfx-default, exact same versions as you and I experience no issues at all when connecting or doing anything in the server

If there is anything I missed in my test I would love to hear that so I can test again

[unknown-urge]

I tested this with a very fresh txAdmin server with Cfx-default, exact same versions as you and I experience no issues at all when connecting or doing anything in the server

If there is anything I missed in my test I would love to hear that so I can test again

Hmm, this is super strange. I can maybe send you in private my crash dump if that would help with anything. On my side, it has a 100% rate occurrence, so this happens everytime I try to run the server via Docker with build 3751.

[yorick2002]

I tested this with a very fresh txAdmin server with Cfx-default, exact same versions as you and I experience no issues at all when connecting or doing anything in the server

If there is anything I missed in my test I would love to hear that so I can test again

Hmm, this is super strange. I can maybe send you in private my crash dump if that would help with anything. On my side, it has a 100% rate occurrence, so this happens everytime I try to run the server via Docker with build 3751.

Sure, my Discord is @yorick

[unknown-urge]

I tested this with a very fresh txAdmin server with Cfx-default, exact same versions as you and I experience no issues at all when connecting or doing anything in the server

If there is anything I missed in my test I would love to hear that so I can test again

Hmm, this is super strange. I can maybe send you in private my crash dump if that would help with anything. On my side, it has a 100% rate occurrence, so this happens everytime I try to run the server via Docker with build 3751.

Sure, my Discord is @yorick

Done.

[yorick2002]

This issue was solved on 05-06 and can be closed. Had to do with some Onesync issue with builds above 3407, after turning Onesync on, there were no issues.