Assertion failed on expression

[SnaiperoG3D]

General
Unity version: 2022.3.29f1
Fish-Networking version: 4.3.5Pro
Discord link: https://discord.com/channels/424284635074134018/1034477094731784302/1066802880151048212

Description
Floating error appears with RollbackManager on server side with client and server setup with parrelsync in 2 windows. Found in Discord 3 messages with this error. One of them have info that for some reason Quaternion null was recorded, but its not. I did debug in placed where new rollback record goes and where lerp goes. There are no null quaternion adds in AddSnapshot method. So i believe that problem in recycle snapshots code part.
Assertion failed on expression: '!CompareApproximately(aScalar, 0.0F)' UnityEngine.Quaternion:Lerp (UnityEngine.Quaternion,UnityEngine.Quaternion,single) FishNet.Component.ColliderRollback.ColliderRollback/RollingCollider:Rollback (FishNet.Component.ColliderRollback.ColliderRollback/FrameRollbackTypes,int,single) (at Assets/FishNet/Runtime/Plugins/ColliderRollback/Scripts/ColliderRollback.cs:113) FishNet.Component.ColliderRollback.ColliderRollback:Rollback (single) (at Assets/FishNet/Runtime/Plugins/ColliderRollback/Scripts/ColliderRollback.cs:401) FishNet.Component.ColliderRollback.RollbackManager:Rollback (int,FishNet.Managing.Timing.PreciseTick,FishNet.Component.ColliderRollback.RollbackPhysicsType,bool) (at Assets/FishNet/Runtime/Plugins/ColliderRollback/Scripts/RollbackManager.cs:281) FishNet.Component.ColliderRollback.RollbackManager:Rollback (FishNet.Managing.Timing.PreciseTick,FishNet.Component.ColliderRollback.RollbackPhysicsType,bool) (at Assets/FishNet/Runtime/Plugins/ColliderRollback/Scripts/RollbackManager.cs:236) DamageRegister:TimeManager_OnTick () (at Assets/Game/Scripts/Player/DamageRegister.cs:84) FishNet.Managing.Timing.TimeManager:IncreaseTick () (at Assets/FishNet/Runtime/Managing/Timing/TimeManager.cs:678) FishNet.Managing.Timing.TimeManager:<TickUpdate>g__MethodLogic|98_0 () (at Assets/FishNet/Runtime/Managing/Timing/TimeManager.cs:342) FishNet.Managing.Timing.TimeManager:TickUpdate () (at Assets/FishNet/Runtime/Managing/Timing/TimeManager.cs:332) FishNet.Transporting.NetworkReaderLoop:Update () (at Assets/FishNet/Runtime/Transporting/NetworkReaderLoop.cs:28)

Replication
Cant find 100% variant to repeat yet. In my case it happens when 50 bots with rollback collider on them

Expected behavior
No errors

[SnaiperoG3D]

I did investigate into rollback code. And i have one theory. rollbackType is determined depends of decimalFrame and _maxSnapshots. decimalFrame depends of TickDelta, but _maxSnapshots setted in Initialize once. So i believe that error happens when Rollback called, but ColliderRollback doesnt have records yet, but _maxSnapshots setted to 2 minimum. In situation for example, when nob with ColliderRollback spawned on tick when Rollback called or + 1 tick. This therory explains why in my case it happens when a lot of bots in game, because my bots killing each other very often

[SnaiperoG3D]

Yes, i was right. Problem appear when nob spawned at same tick when Rollback call. I did logs when bot spawned and when Assertion failed error appear. Both errors goes to same nob when click on them.

Assertion failed appears on nob what was spawned at same tick, 701 in this case.

[SnaiperoG3D]

Also i have info about why i can so easily find it, cuz it should be hard to catch in first thouths. I have i guess unique case again. My player attack have around 15-30 tick long. So instead of sending PreciseTick each frame, i do send PreciseTick on start attack, and do increase Tick of PreciseTick on server each tick. I guess it can be helpfull for unit tests and etc.

[SnaiperoG3D]

There is my temp solution. ColliderRollback.cs. Add two vars

private int _writeCount = 0;
private bool _writeDone = false;

In ResetSnapshots method reset them

_writeCount = 0;
_writeDone = false;

In AddSnapshot method check that we have atleast 2 recorded frames

if(!_writeDone)
{
    _writeCount++;
    if (_writeCount >= 2)
        _writeDone = true;
}

And last in main Rollback method, where transform changes add check for _writeDone in method begining

if (!_writeDone)
    return;

The point here is to return in Rollback method if there are less then 2 records for rollback

[FirstGearGames]

Fixed in 4.4.0. Ty again for the find.