If two or more Fractalguardian2 using the steamcannon, joining the game midway may result in abnormal synchronization.

[zhu-rengong]

Disclaimers

• I have searched the issue tracker to check if the issue has already been reported.
• My issue happened while using mods.

What happened?

As the title saying, when you join the game mid-round, there are no characters on your game screen, it's completely still and silent, However, in multiplayer, you can hear other players talking through voice chat.

I checked the source code and found that the issue is related to the attack cooldown. When the attack cooldown is very low, the server will create a large number of events (SetAttackTarget and ExecuteAttack). The following command can be used to show statistics of all events related to entities with the specified identifier:

#if SERVER
DebugConsole.Commands.Add(new DebugConsole.Command("showevents", "showevents <identifier>", (string[] args) =>
{
    if (args.Length == 0 || args[0].IsNullOrEmpty()) { return; }
    Identifier identifier = args[0];
    if (!CharacterPrefab.Prefabs.ContainsKey(identifier)) { return; }
    var characterPrefab = CharacterPrefab.Prefabs[identifier];
    string msg = $"{characterPrefab.Name} (content package: {characterPrefab.ContentPackage.Name})";
    var eventTypes = GameMain.Server.EntityEventManager.UniqueEvents
        .Union(GameMain.Server.EntityEventManager.Events)
        .Select(e => e.Entity is Character character && character.Prefab == characterPrefab
                ? (e.Data as Character.IEventData)?.EventType
                : null)
        .Where(t => t.HasValue)
        .ToList();
    var sorted = eventTypes.GroupBy(t => t)
        .Select(g => new { EventType = Enum.GetName(typeof(Character.EventType), g.Key), Count = g.Count() })
        .OrderByDescending(v => v.Count);
    foreach (var v in sorted)
    {
        if (!msg.IsNullOrEmpty()) { msg += "\n"; }
        msg += $"EventType: {v.EventType} (Count: {v.Count})";
    }
    DebugConsole.NewMessage(msg);
}, () =>
{
    return new string[][] { CharacterPrefab.Prefabs.Select(prefab => prefab.Identifier.Value).ToArray() };
}));
#endif

Due to the large size of the video, I have split it into four parts:

test.4.00_00_03-00_00_10.mp4

test.4.00_00_16-00_00_21.mp4

test.4.00_00_27-00_00_29.mp4

test.4.00_00_34-00_00_50.mp4

Reproduction steps

1. spawn 2 or more Fractalguardian2
2. type in godmode ensure you can't die
3. disconnect from the server and join midway
4. ensure that Fractalguardian2 are using steamcannon when you're getting sync

Bug prevalence

Happens every now and then

Single player or multiplayer?

Multiplayer hosted from the in-game menu (= using a listen server)

-

No response

Version

v1.7.7.0 (Winter Update)

-

No response

Which operating system did you encounter this bug on?

Windows

Relevant error messages and crash reports

No response

[zhu-rengong]

Other players have also encountered this issue: #15597
I believe he had enabled the "EuropeWar" mod, which includes many monsters that use ranged weapons with equally low attack cooldowns.

[A2ur3]

#15436