Performance degraded on a single savegame. Output log run amok. Is this savegame corruption or something else?

[Daedrokh]

I started playing UBOAT about a month ago, got to 150+ hours on my first savegame, and the past 10 or so hours I've noticed this strange drop in performance where previously it was running smooth as silk on extreme graphics settings.

No issues with other games, and no issues starting new UBOAT saves which run smooth.

My original 150+ hour save, however, is chugging and stuttering and FPS dropping like there is no tomorrow. I checked this board and online for possible solutions, tried the usual recommendations, but to no avail. I was perplexed at the severe degradation of the game performance when playing this save until I noticed the output_log.txt was over 6 GB in size (around the time I did the cache/data sheets/temp folder purges. I thought this is extremely large for a logging file, so began investigating.

The log was so large I couldn't open it even in Notepad++, so I decided to test the logging from a fresh new game versus the logging when loading up my 150+ hour savegame, and what I clearly noticed was once the 150+ hr savegame loaded up, the output log would spam the same System.NullReferenceException over and over again, at a rate of 1MB a second in filesize growth.

Here's the header of the log as an example:

Initialized Injection Framework in 10300 ms.
Engine version: 2021.3.33f1
System version: Windows 10  (10.0.19045) 64bit
System memory: 32620 MB
Direct3D:
    Version:  Direct3D 11.0 [level 11.1]
    Renderer: NVIDIA GeForce RTX 4070 Ti
    Vendor:   NVIDIA
    VRAM:     11996 MB
    Driver:   572.83
There can be only one active Event System.
Game version: 2025.1 Patch 12
There can be only one active Event System.
Loading save file: North-East Atlantic - 1943.8 - 1.
Loading interior scene Type VIIC41 Interior.
GarbageCollector disposing of ComputeBuffer. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.
System.NullReferenceException: Object reference not set to an instance of an object
  at UBOAT.Game.Scene.Entities.Rocket.OnEnable () [0x00006] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
System.NullReferenceException: Object reference not set to an instance of an object
  at UBOAT.Game.Scene.Entities.Entity.SetHighlightColor () [0x00021] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.Scene.Entities.Entity.Start () [0x00000] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.Scene.Entities.Observator.Start () [0x0000c] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.Scene.Entities.Ship.Start () [0x00000] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.Scene.Entities.Aircraft.Start () [0x00000] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 

Then occasionally the log will post this event in between the usual spam noted above.

System.InvalidOperationException: Entity named "Short Sunderland" has a null country assigned to it.
  at UBOAT.Game.UI.Notifications.UndetectedNotification.UpdateDominantObservationType () [0x00051] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.UI.Notifications.UndetectedNotification.Update () [0x000d6] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 

About 300 or so lines of log events the initial group of exceptions reduces to just two:

System.NullReferenceException: Object reference not set to an instance of an object
  at UBOAT.Game.Scene.Entities.Ship.Update () [0x0010c] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 
  at UBOAT.Game.Scene.Entities.Aircraft.Update () [0x00000] in <016dc6bc5dfa4fa7bda40f4b972c09ab>:0 

Here is a pastebin link to the first 5000 lines of logging if anyone is interested: https://pastebin.com/7cDybLXG

The very first line before the exception spam starts is:

GarbageCollector disposing of ComputeBuffer. Please use ComputeBuffer.Release() or .Dispose() to manually release the buffer.

I don't know enough about Unity or programming to know if this is telltale sign of a memory leak in VRAM or RAM or what. All I know is the game played flawlessly for 150 hours and then my game performance on just this one particular savegame went very bad. The exceptions being thrown in the log are happening at such an incredible rate that it's affecting overall system performance ONLY when trying to play this savegame.

Anyone seen anything like this before? Is this what savegame corruption looks like, or possibly something else? Maybe one of the recent patches hosed it up?

Hoping the dev sees this and weighs in, too.

[Sword]

there is a memory leak, long loading of the shore and ships, and it doesn't matter, one ship or a whole convoy, before the latest patches it was also normal, I started a new game without mods, the same thing happens

[Sword]

Loading in the background still loads when the ship is already visible visually, with the shore everything is sad, hop and it is in front of your nose, other people had problems with loading the bottom, I have the game on an SSD, there are definitely problems with memory leaks here.

[Bogus]

Yeah, I have the same issue, just saying so maybe this post can get more attention

[gp913]

Same here, I have 237 hours and the game used to run smoothly. I hardly play now as after 5 mins of playing it is a stuttering mess with 100% GPU usage which never used to occur and changing settings makes no difference. I reported it before and heard nothing back.

[Blitzen Trap]

Same here. Game eventually became completely unplayable with VERY long stutters. It is always worst when a ship is detected, or near a shore line it seems.

[Finess]

Same here.

[Daedrokh]

I went back to an older manual save somewhere around 1941 in the campaign which did not exhibit the performance degradation and replayed from there.

I just finished The Last Stand on this new savegame timeline and performance is nominal.

I think best practice to avoid a screwed savegame (I hesitate to call it corrupted, since it could still be loaded and played with terrible performance due to the exceptions in the log) is to make frequent manual saves you can fall back to if you ever see a savegame with performance degradation like I did, where other saves or new games had no performance impact.

[stullenandy]

Finally, I'm no longer alone with this problem. I thought my system had an error for my favorite game. For me, freighter in sight, everything is already loaded, the loading symbol starts again and the game starts to stutter. During thunderstorms near land, permanently jerked. Please finally get this shop in the background under control, it is currently breaking the game. I'm keeping my fingers crossed that you can fix it.

[Pit_Pinsel]

Hi Pit Pinsel her the Twitch streamer, you can also see it in my streams that the performance troping down after the first 2 hours. That must be fixed, this performance killed my complete game fun to zero. I played this game for 2100 hours and i have never a performance like that.

[The duckman]

i'm having the same damn issues i'm at my 4th/5th patrol. new save works fine but my save is borked. really hope there's a fix for this... i had a really good start and i dont want to restart! if i have to restart i'll probs just delete this and get Silent Hunter lll installed. i really wanted to have a good time playing but this game has awful technical issues

[Pit_Pinsel]

I also don't know why something as massively important as the functionality of a game is ignored here for so long, but this is definitely a mistake, or is this the wrong place to post this?

[Blitzen Trap]

Cant for the life of me get rid of the progressive lag. Even tried a fresh install, unmodded, new career start and still...eventually the save gets borked.

[The duckman]

Originally posted by Blitzen Trap:

Cant for the life of me get rid of the progressive lag. Even tried a fresh install, unmodded, new career start and still...eventually the save gets borked.

good to know i made the right choice uninstalling then, shame i cant refund it

[Pit_Pinsel]

Please everyone put an f11 in the game and link this post here, if they continue to ignore us we will unfortunately have to start torpedoing they with nasty reviews.

[CAS]

Same here, bad stuttering