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ilgoehring13

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Jun 13, 2025
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Information​

When reporting a crash, stability or performance problems, please ensure that you have the files ready for submission​

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Required​

Summary​

Critical system update error during Serialize->SerializerSystem

Steps to reproduce​

During normal gameplay, if I attempt to save via the main menu or if an autosave initiates, this [CRITICAL] error occurs, prompting me to choose between continuing, saving and quitting, or quitting. If I attempt to save, it will just run endlessly, and if I press continue, I can still play, but I am unable to attempt a save again.

Expected Result​

I should be able to save or have an autosave initiate without a crash.

Actual Result​

Crash with this error:

[CRITICAL] System update error during Serialize->SerializerSystem:

NullReferenceException: Object reference not set to an instance of an object
at Unity.Entities.EntityManager.HighestEntityIndex () [0x00053] in <e125b05a4c73402481185d1a135059f5>:0
at Colossal.Serialization.Entities.EntitySerializer`1[TWriteBuffer].CreateEntityTable (Colossal.Serialization.Entities.Context context, Unity.Collections.Allocator allocator) [0x0017c] in <f539b356a552460880371c76b71887be>:0
at Colossal.Serialization.Entities.EntitySerializer`1[TWriteBuffer].Serialize[TWriter,TFormatTags] (Colossal.Serialization.Entities.Context context, Unity.Entities.EntityQuery query, Colossal.Serialization.Entities.BufferFormat bufferFormat, Unity.Entities.ComponentType[] requireEnabled) [0x0004d] in <f539b356a552460880371c76b71887be>:0
at Game.Serialization.SerializerSystem.OnUpdate () [0x000c4] in <cc2da3314a404c70a203f382286b5d52>:0
at Unity.Entities.SystemBase.Update () [0x0004e] in <e125b05a4c73402481185d1a135059f5>:0
at Game.UpdateSystem.Update (Game.SystemUpdatePhase phase) [0x0004e] in <cc2da3314a404c70a203f382286b5d52>:0
Colossal.Logging.CustomLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:LogFormat(LogType, String, Object[])
Colossal.Logging.UnityLogger:Log(Level, String, Exception)
Colossal.Logging.UnityLogger:CriticalFormat(Exception, String, Object, Object)
Game.UpdateSystem:Update(SystemUpdatePhase)
Game.Serialization.SaveGameSystem:OnUpdate()
Unity.Entities.SystemBase:Update()
Game.UpdateSystem:Update(SystemUpdatePhase)
Game.SceneFlow.GameManager:UpdateWorld()
Game.SceneFlow.GameManager:Update()

Game Version​

1.3.3f1

Affected Feature​

  • Save

Platform​

  • Steam

Save Game​

View attachment Sealtown Beach 4 - pp.cok

Crash Dump and Logs​

View attachment [CRITICAL] System update error dur.txt

Additional Information​

Additional Information​

I don't get a proper crash - it just rolls endlessly - ergo I don't have a crash dump. I've included the error log.

Screenshot or Video​



 
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Reactions:
If it is a mod then which one is causing it. Its a catch 22 really, we need the extra tools to enjoy building but if something goes wrong like it is now for lots of people it makes it very hard to work out what changed in the release and what conflict is it causing to the mods that have been updated
 
If it is a mod then which one is causing it. Its a catch 22 really, we need the extra tools to enjoy building but if something goes wrong like it is now for lots of people it makes it very hard to work out what changed in the release and what conflict is it causing to the mods that have been updated

What happens if you disable the mod Anarchy? Does it make any difference?
 
I too am having the same issue. I run a minimal modset of most of the region packs (minus French) and around 20 code, asset and map mods, nothing outlandish, just the usual stuff CO probably should have baked into the real game.

Had issues with this in a preivous save file which has blocked me from viewing it from the loading screen, and now after starting a new save I have came up against the same issue almost an hour in. However, this time it will let me see the save file in the load save menu but clicking it won't work... smh.

Guess its the usual of can't play the game until either a hotfix, or modders work out what is broken but it's so frustrating.
 
The same misery with every game update! Many mods need to be updated, and this time it seems as if there are problems that can't be resolved (so quickly). Sorry, but you can't play reliably like this! It would be helpful if error messages could reference the defective mod. The developers are washing their hands of any blame and leaving the modders in the lurch.:(
 
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The same misery with every game update! Many mods need to be updated, and this time it seems as if there are problems that can't be resolved (so quickly). Sorry, but you can't play reliably like this! It would be helpful if error messages could reference the defective mod. The developers are washing their hands of any blame and leaving the modders in the lurch.:(
Please keep in mind that mods are always a game extension, the developers cannot change their code to make sure mods keep working. The focus is always for the base game to be the best it can be. Mods have to do their work to stay up to date.
 
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Reactions:
An update to my original post. I had this issue and reset the load order of the mods. You can do this for each mod playset. I noticed the unified icon library dependency mod was moved to the top of the load order so maybe it needs to load first. I played all day on Sunday and the error did not occur again.
 
I saw somewhere but can't find it on reddit that this problem is caused by using anarchy and using the constant slope option when placing roads. I haven't tested that, i'll test this afternoon after work.
 
Thanks for testing that. It looks like your issue ist most likely related to mods then. Unfortunately we cannot assist with save games that have been used with mods, as there are too many variables to account for. Please create another thread if you ever encounter that issue in a save without any mods.
As just another player in the community, I would like to confirm what pdx_Mimonsi here, is saying. This error is almost certainly induced by mods. I was building a city with mods (begun before the latest update) and this error would occur randomly every few hours. After the latest update, the error continued to happen. When I started a new city completely without mods, after the new update, the error "disappeared", as in it has not occurred in over 5 days of playing, including almost 30 hours of the game running completely unattended (and without the error occurring).

Hopefully this error is caused by an active mod and not one just sitting in our library, so here is the list of mods in my active playset at the time when the error was occurring (in load order):

ExtraLib
l18n EveryWhere
Anarchy
Traffic
Unified Icon Library
Zoning Toolkit
529 Tiles
Water Features
Move It
Zone Color Changer*
ExtraLandscapingTools

*: I doubt the error is caused by Zone Color Changer, as I added that mod well after I began to run into the Serialization error.
 
Is there any update on this?

I've been having this issue since the last patch update, which mod is causing the issue?

Skyve has been no help with this, I've lost so many saves now. (yes that's my fault, learnt the hard way. I should have been backing up my saves)

However the game is unplayable at present.