@FighterAndi(DK)
there is nothing that can be done about it from modderside as its caused from either se side or steam side or the conneciton between server and workshop servers or th efiles handling the communication.
i linked to some additional steps that can be done to alleviate it that are pinned on the wc discord, though if its a third party host you might need to go through the support for them.

i have a HostHavoc server myself, and have tried a bunch of possible fixes, but it just keeps comming up with this info and won´t start the server properly..
if i remove ANY mod it says is failing, it just puts a new one up, but it seems to be focused on Weapon Core..

Downloading: Id = 'WeaponCore - 2.5'
MyDefinitionManager.GetSessionPreloadDefinitions() - END
MySandboxGame.PerformPreload() - END VANILLA SOUNDS AND VOXELS
MySandboxGame.PerformPreload() - END
Workshop item with id WeaponCore download finished. Result: k_EResultFail
Workshop item with id WeaponCore download finished. Result: k_EResultFail
Error during downloading: Fail
Mod failed: Id = 'WeaponCore - 2.5'
Failed to download mod: Id = 'WeaponCore - 2.5'
Downloading mods failed
Downloading world mods - END
Unable to download mods. Result = 0
MySandboxGame.Initialize() - END
Session can not start. Save is corrupted or not valid. See log file for more information.

@FudgeYeah | Heaven
the "2025-08-17 11:05:07.100 - Thread: 28 -> Workshop item with id 3154371364 download finished. Result: k_EResultFail" is usually caused by a connection problem and in rare cases by file corruption but in that case it happening with all mods as it would be a serverside file corruption of the files facilitating the mod integrety check or connection to the workshop servers.
it is usually gone after a while, but if that isnt the case you will need to do some more steps that aree inside a pinned post on the wc discord https://discord.com/channels/804196269072711720/805169009384226866/998607335889051668 , just keep in mind that if its via a third party host its possible you need to do them via the support.

Can´t install it on HostHavoc servers.

Mod query successful
2025-08-17 11:05:01.939 - Thread: 12 -> Downloading: Id = 3154371364, title = 'WeaponCore - 2.5'
2025-08-17 11:05:07.100 - Thread: 28 -> Workshop item with id 3154371364 download finished. Result: k_EResultFail
2025-08-17 11:05:07.100 - Thread: 28 -> Error during downloading: Fail
2025-08-17 11:05:07.100 - Thread: 12 -> Mod failed: Id = 3154371364, title = 'WeaponCore - 2.5'
2025-08-17 11:05:07.100 - Thread: 12 -> Failed to download mod: Id = 3154371364, title = 'WeaponCore - 2.5'
2025-08-17 11:05:07.100 - Thread: 12 -> Downloading mods failed

@Justducky2407
as its always a possibility:
did you check for file corruption?

if you already did that please take logs and an example world and report in on the wc discord with an as good as possiblke explanation of what isnt working.

the update that came out today broke all weapon core weapons completely

@DeltaWing
please try again as a quick fix has been deployed.

The update occured about 5 minutes prior to my post here lol it literally just broke

@DeltaWing
there was a wc update today so maybee something got wrong with updating the files, so please verify they have been updated properly.

if that doesnt help please take logs and an exampleworld and do a report on the wc discord.

Idk what you did but suddenly every single gun is firing when I click regardless of trigger mode settings

@gachd
the multiple thread thing is a false detection that comes up now and then and can be ignored.

Is this multiple thread issue fixed? Shift F1 is still throwing the same error with SS in the .2-.1 range.

Happy the change mostly fixed the issues with performance, thanks wc devs

there was some changes made to revert some changes made in the update and the first testers report success.
if anyone still has probs with massive simspeedkill or a parallel thread warning please report in on the discord.

@EscapedSheep
errors can be caused by a bunch of stuff and without having the full pictures its impossible to tell what the cause it, so please take the complete log and provide it on the wc discord.

the one about parallel threads you postet comes up every now and then even though wc doesnt use parallel thread stuff, so it isnt something new just something that doesnt hit always and usually not everyone.

the logs are capable to show if everything works as it should and what could maybee cause probs du to conflicts and thus can help sort it out.

The only related part of the log that is new is the error i posted before.

@EscapedSheep
its always possible that a modupdate introduces new probs due to the changes or due to other stuff involved in that update.
the logs are the absolut minimum that is needed to sort through that.

But this mod was the only one that updated and now its an issue? Hmmmm?

@all that get the parallel physics warning

going to repeat what was said in the past multiple times in the steam comments and on the wc discord from multiple modders:
wc itsealf does not touch parallel threads physics and it is a false detection of keens system to detect it.


if you dont believe me you can go on the search for the original comments that stated that either in the steam comments (though its wuite possible that they where on the old wc workshoppage under darkstar and thus are no longer easily findable) or on the wc discord.
-----------

@all that have simspeed probs with wc in use

for your simspeed problem more informations in form of atleast the logs would be needed for analysation, prefered providing point would be the wc discord.

Yep our dedicated is now running at 0.3 sim after update.

```
Error: Mod WeaponCore - 2.5 is accessing physics from parallel threads. This is not safe and might cause the game to crash or behave unexpectedly.
```

@BDCarrillo

same problem here :(

jap same here

Occurs also on dedicated servers, extreme Server Simulation CPU load. Affects all weaponcore-based mods. Please release a fix soon.

Same issue. Thread CPU get a lot of stress. Then, the game lags.

Same problem here with the lags and parallel threads warning

@Valdar - Same for me. Check Shift-F1: My game is saying the followiing: Weaponcore 2.5 is accessing physics from parallel threads. this is not safe and might cause the game to crash or behave unexpectedly.

I have a mild issue, my game lags like crazy and it only started happening after the august 1 update. Is this happening to others or is it an issue on my side?

That was the issues! I was editing the sandbox.sbc, not sandbox_config.sbc. Thank you for that. Also, changing the render distance via the ingame options doesn't work. Found out that all the render distance does in world settings is change voxel rendering. So I dropped it from 50km to 20km

I hope Keen adds a slider to change sync distance. But with them working on SE2 I don't see that happening anytime soon. Hopefully that add it as a base feature is SE2 when multiplayer drops some time next year

@D3ATHCOM5
if you want someone with deeper knowledge of the codestuff behind it that can explain it in more detail you wil lbe able to find them on the wc discord.
i am just a player myself even though i got some knowledge to work with that a collectet over the years the modders on the wc discord have a far deeper understanding of the background mechanics.


- - - - - - - -
cursed letter limit in the comments :(

@D3ATHCOM5
the unloading at just above 3km would mean that you viewrange/syncrange is set at 3km, if you have no wc based mod in and just wc there shouldnt be any weapon that would be able to shoot further than roughly halve that dustance and thus you should be able to shoot at them as they would need to be far inside viewrange/syncrange to shoot at you.

just took a look and the longest range would be 2km with no ai block and 2.5km with the defense or offense ai block (giventhe shpts dont depsawn before reaching the distance) which are both distances where the grid should be inside the syncrange to shoot at stuff.
and the shortest syncrang readily avaible inside the ingame worldsetting is 5km with 15km beeing the default.
once again: wc has no influence on stuff beeing rendered or not, the viewrange/syncrange and it can only work with whatr se provides it in that regard.

@D3ATHCOM5
the rendering of the stuff is relevant to viewrange/syncrange and in some cases even your graphic settings.
viewrange/syncrange can be changed in worldsettings with a dropdown menu or via the sandbox_config.sbc with the world settings in it.
wc has no influence on the viewrange/syncrange and can only work with what se gives it to work with.
from my own experience even in a full vanilla world once stuff is outside syncrange/viewrange it isnt beeing shot at or beeing hitable by weapons.
though that throws up the question how the npc grid could fight each other if they werent even activly loaded, maybee some very barebone fighting calculations?

The issue is that grids aren't being rendered unless they're within 3km. The weaponcore weapons aren't shooting at them until they're within 3km, because the grids aren't rendered. But because my friends and I are near are base and, which is therefor rendered, the enemy AI ships can shoot our base. But we can't retaliate unless we grab fighters and go fight them.

The main issue we're having is that the antenna's are getting shot off during AI vs AI combat and they then strafe past our base unloading their guns into our base.

The video was just showing that the grids are being unloaded at 3.01km

@D3ATHCOM5
oh and please also make sure you dont use wc as a local mod and use the workshop uploaded version and have steam in online mode, you video shows you did put the world into friends mode but from my own experience this can be done regardless of if steam is in online or offline mode.

standard first aid list (file paths may vary for servers or non windows users or servers) (s for needs to be done on server/host and client side):
- make a testworld just with the affected mod and one of the other mods as a mod conflict test, don't forget the mod requirements.
- (s) make a file integrety check for space engineers itself.
- (s) delete all modrelated data of the affected mods in the main and world specific storage folder and let it regenerate in case this got corruptet (findable under %appdata%\spaceengineers and %appdata%\spaceengineers\saves\yoursteamid64\yourworldname).
- (s) delete all modrelated data of the affected mods in the workshop folder and redownload it to neutralize eventually data corruption by modupdate (files are findable inside the workshop folder of the steam library folder in which you have installed space engineers).

@D3ATHCOM5
the vfx thing is something that would require a modside reqork to my understanding at point of writing.

in your video its not clear to see which weapons are used and you are multiple km (outgoing fro mantenna signal) out at which you wont have any turret shooting with just wc in the world as wc itself doesnt change anything on the vanilla weapons besides making them wc compatible, so you wills still have vanilla ranges.
besides that outgoing from the color of the antenna its a allied grid and thus would neither way shoot on you.

if you cant get them to shoot on armed enemy grids that are in range and inside the weapons aming area than please try if the "standard first aid list" helps and if that doesnt help please report in on the wc discord with and example world (a world with a premade situation for problem analysis and with no more mods than absolutly neccessarty including mod requirements) and logs from a test in that world.

Also, how do I disable vfx, mainly gunsmoke, it tanks fps. Going from 120+ down to sub 30 after firing a few seconds

Anyone know how to fix this? Editing the .sbc does not work, even setting it to readonly doesn't work. Weaponcore is literally unusable as AI ships just sit outside render range and destroy our base and our turrets don't shoot back. Evening trying to take them down manually using the ships antenna as a rough estimate doesn't work, they don't seem to take damage unless visible

https://youtu.be/s6VBxG3YR3c

@Too Wide, i'm on Nitrado as well. Doing the file move trick worked for me. The one @Athane posted.

@everyone
I forced my server to update and solved this problem
My server re-downloaded this mod and it updated.
My server is up and running :)

@Abisius Xarvenius Carbensius

I'll give it a go, thank you.

@Too Wide
2 possibilitys to try that are know atm if time alone doenst help:
1- a forced server update which is usually done through the steam cmd and third party server providers (for example: nitrado, gportal) can have a button for it or do it via the support
2- either you need to contact the support to do it or give you the neccesary access or if you already have the neccessary access try what was posted just before your post

Athane спасибо!
It helped

Having an issue with Nitrado sever not downloading the mod.

From previous comments I can see it's a steam issue and not a mod issue, so commenting just to see if anyone announces it's fixed or comes up with a workaround for Nitrado.

I found a fix that worked for me.

"Copy the following files from your Steam client location (Program Files (x86)\Steam\) Into your Dedicated Server (SpaceEngineersDedicatedServer\DedicatedServer64\:

steamclient.dll


steamclient64.dll


tier0_s.dll


tier0_s64.dll


vstdlib_s.dll


vstdlib_s64.dll


Make sure you COPY (and overwrite) them and NOT MOVE them. If you are using DS on your local machine, the files may move if they're on the same root drive. All the files may not be necessary, but I just copied all of them for good measure."

Found on this link... https://support.keenswh.com/spaceengineers/pc/topic/dedicated-server-exception-while-loading-world

@КОЛЯН @Athane
one way that helps sometimes has already been written by me:
"try if forcing the server to update helps"
you can do this via the steam cmd and telling it to check the files.
if you have the server via a third party provider the support might be needed to do it depending on how they have set it up.

there is also a pinned comment on the wc discord that has some more advanced steps listet.

Captain, Thank you for your response, I understand, we will wait for possible solutions.
Athane, please let us know if you find a solution to the problem.

Server has been down all day with the "k_eresultfail" issue. I am starting to look at ways to bypass it or just remove this mod to bring the server back up.

@КОЛЯН Yes, like the others here, it's Steam's fault, not the mod's

Crash server :(
k_eresultfail

@CCIG-Oskar (elfikcom)
look if you have somewhere a "k_eresultfail" in that log, if that is the case you will need to either wait and hope if it solves itself or try if forcing the server to update helps.

either way downloadprobs are usually down to probs in the connection to the steamworkshop servers, the steamworkshopservers themself or another system connectet to the download of stuff from the steamworkshopservers.