as a temp fix, is their any chance you could make a version of the this mod that removes all the ranged weapons as they are the only ones that cause the desync, that way we could us the primarch mod as well. <3

No, sorry, thats far too much work for a 'temp' fix.
which weapons are actually casuing it? it cant possibly be all of them, since some use purely vanilla mechanics

when playing MP whenever a modded weapon hits a target the game desyncs. Desync logs: It seems to point towards issues with explosive bullets

Trace of first desynced map random state:
142 Tick:30012 Hash:-587369412 ''
at Verse.Rand.Verse.Rand.get_Value_Patch1 () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.Rand.Range (System.Single min, System.Single max) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.Mote..ctor () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.MoteThrown..ctor () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters, System.Exception& exc) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.RuntimeType.CreateInstanceMono (System.Boolean nonPublic) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.RuntimeType.CreateInstanceSlow (System.Boolean publicOnly, System.Boolean skipCheckThis, System.Boolean fillCache, System.Threading.StackCrawlMark& stackMark) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.RuntimeType.CreateInstanceDefaultCtor (System.Boolean publicOnly, System.Boolean skipCheckThis, System.Boolean fillCache, System.Threading.StackCrawlMark& stackMark) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.Activator.CreateInstance (System.Type type, System.Boolean nonPublic) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at System.Activator.CreateInstance (System.Type type) [0x00000] in <567df3e0919241ba98db88bec4c6696f>:0
at Verse.ThingMaker.MakeThing (Verse.ThingDef def, Verse.ThingDef stuff) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at AdeptusMechanicus.EffectProjectileExtension.ThrowMote (UnityEngine.Vector3 loc, Verse.Map map, Verse.ThingDef explosionMoteDef, System.Single explosionSize, UnityEngine.Color color, Verse.SoundDef sound, Verse.ThingDef ImpactMoteDef, System.Single ImpactMoteSize, Verse.ThingDef ImpactGlowMoteDef, System.Single ImpactGlowMoteSize, Verse.Thing hitThing) [0x00000] in <7b5fe87fd00b415587ce37ebe953e694>:0
at AdeptusMechanicus.HarmonyInstance.Projectile_Impact_ProjectileExtension_Patches.EffectProjectileExtension (Verse.Projectile __instance, UnityEngine.Vector3 vector, Verse.Thing hitThing) [0x00000] in <7b5fe87fd00b415587ce37ebe953e694>:0
at AdeptusMechanicus.HarmonyInstance.Projectile_Impact_ProjectileExtension_Patches.Prefix (Verse.Projectile& __instance, Verse.Thing& ___launcher, Verse.LocalTargetInfo& ___intendedTarget, Verse.Thing hitThing) [0x00000] in <7b5fe87fd00b415587ce37ebe953e694>:0
at Verse.Projectile.Verse.Projectile.Impact_Patch1 (Verse.Projectile , Verse.Thing ) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at RimWorld.Bullet.Impact (Verse.Thing hitThing) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at AdeptusMechanicus.Bullet_Explosive.Impact (Verse.Thing hitThing) [0x00000] in <7b5fe87fd00b415587ce37ebe953e694>:0
at Verse.Projectile.ImpactSomething () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.Projectile.Verse.Projectile.Tick_Patch3 (Verse.Projectile ) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at AdeptusMechanicus.Bullet_Explosive.AdeptusMechanicus.Bullet_Explosive.Tick_Patch2 (AdeptusMechanicus.Bullet_Explosive ) [0x00000] in <7b5fe87fd00b415587ce37ebe953e694>:0
at Verse.TickList.Tick () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Multiplayer.Client.MapAsyncTimeComp.Tick () [0x00000] in <835b0905e8094d25b9a774f7f86b5f59>:0
at Multiplayer.Client.TickPatch.TickTickable (Multiplayer.Client.ITickable tickable) [0x00000] in <835b0905e8094d25b9a774f7f86b5f59>:0
at Multiplayer.Client.TickPatch.Tick () [0x00000] in <835b0905e8094d25b9a774f7f86b5f59>:0
at Multiplayer.Client.TickPatch.Prefix () [0x00000] in <835b0905e8094d25b9a774f7f86b5f59>:0
at Verse.TickManager.Verse.TickManager.TickManagerUpdate_Patch2 (Verse.TickManager ) [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.Game.UpdatePlay () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0
at Verse.Root_Play.Update () [0x00000] in <c36f9493c9844ddaa7fb5c788416098f>:0

seen quite a few ppl checking the multiplayer discord if ur adeptus mechanicus mods are working with the MP mods.
Think a lot of ppl would be very happy if you have the time to have a look at it sometime myself included ;)

@sniXer
that looks like i just forgot to wrap a rand value in a state push/pop, in the next release, ive rebuilt alot of that system already, and a quick look tells me that its all wrapped, as far as i can tell at least.

its tricky for me to test, i cant seem to get the arbiter to connect to me at all, can you test the current github build? you will need to use the github builds of any of these mods your using if you do

Originally posted by sniXer:

when playing MP whenever a modded weapon hits a target the game desyncs. Desync logs: It seems to point towards issues with explosive bullets

Fixed for next release

I personally noticed that weapons using the games normal projectiles did not cause desyncs so I tested a couple of the different weapons from different races.

An easy to reproduce example: (for those who can)

Imperial missile launcher, fire a frag missile, no desync. Fire a krak missile, desync.

This is what I have so far
+ = doesn't desync
- = causes a desync

Imperial

autogun +
exitus +
Bolters -
Volkite -
Autocannon -
Las Cannon -

Dark Eldar (weird sample here, DE seems to be mostly desync free)

Splinter Cannon +
blast pistol +
Darklance +

Ork

Big Shoota +

Necron

Gauss Blaster +

A super lazy way to patch this mod for MP could be to just have a version without the desync causing weapons.

Originally posted by Ogliss:

its tricky for me to test, i cant seem to get the arbiter to connect to me at all, can you test the current github build? you will need to use the github builds of any of these mods your using if you do

I tested your github version arbiter wouldnt connect to me either.
The arbiter connects when using the workshop version, the github version prevents/breaks the arbiter connecting.