PhysBone not working properly
available in future release
りきゅー
When I loaded an avatar that has an animation to toggle PhysBones on/off, all PhysBones (even those not controlled by the animation) stopped working.
Once I played an animation that toggles any PhysBone on/off, they started working properly again.
If I reset the avatar, they stopped working again.
Strangely, when someone else resets or loads the avatar, the PhysBones start working normally.
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Tukumomi
This information is from the 25th (before the update that was applied at 5:00 AM on the 26th), but a friend of mine encountered the following bug.
Everyone was using the standard (non-beta) version.
Everyone in the instance goes into a T-pose
PB/Contacts remain stuck in place (see attached image)
Constraints and Final IK stop functioning
The behavior of Contacts hasn’t been fully confirmed, but since all Avatar Dynamics seem to have stopped working, it’s likely that Contacts are also affected in the same way.
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available in future release
DragonAsh
This is still an issue after the update, just not as bad.
My PB broke randomly as I was using my avi and it kept on lagging out my game every few seconds after it happened. Had to quit and restart, but it was def due to the PB break
DragonAsh
Correction. This is consistently happening AND its not either crashing my game and even sometimes my entire PC. I've tested this in VR and desktop mode with the same results.
This happens on both live avatars and local only test avatars
StormRel
Merged in a post:
Physbones locking up
ZeirTheFox01
On my avatar, the Physbones seem to lock up and they unlock themselves when I do the fist. Example in video.
StormRel
Merged in a post:
Avatar bones broken
TempestFur
So i just logged in after latest updates and my avatars bones a locked like there being pushed to the side. i have used this avatar for some time without issue. no after update its broken. reupload fixed nothing and all is fine in unity.
some avatars are ok others not
みそみそ
📝 [Forum Post Template: Hypothesis-Based Information Offering]
Title:
Possible PhysBone Freeze Cause When Meshes Are Toggled Off at Avatar Load (Needs Confirmation)
Body:
Hi, I'm not 100% sure about this yet, but I wanted to share a possible cause of the local PhysBone freeze issue that might help with identifying or confirming the underlying problem.
⚠️ Observed Behavior
In certain situations, especially in dance-heavy worlds like MR MMD World, I noticed that PhysBones freeze locally after the avatar loads. This typically happens when the avatar is loaded in a state where some PhysBone-related objects are disabled or hidden (for example, clothing or hair parts).
In my case:
PhysBones on hair and chest freeze after dancing, but only when clothes are toggled off
This freeze doesn't resolve even if toggles are switched again
Reentering the world sometimes helps, but the problem returns after dancing again
✅ Tentative Workaround (Still Testing)
What seems to reduce or eliminate the freeze for now:
Keeping all PhysBone objects and Armature bones active at all times
Only toggling off SkinnedMeshRenderer objects (not the entire GameObject)
I’ve been testing this for a couple of hours now, and so far, PhysBones seem to behave more consistently even after multiple dances and reloading events.
🧠 My Hypothesis (Needs Review)
PhysBone components might only initialize correctly if their GameObjects are active at the time the avatar is loaded. If they're inactive (e.g., toggled off clothing mesh containing a PhysBone), they might not get properly registered, causing local simulation failure.
However, this is still just a guess — I’m sharing it in case it aligns with others’ experiences or helps narrow down the root cause.
🧩 Possibly Related
I’ve also seen this forum thread, which seems to describe a deeper-level issue:
“All PhysBones break across all avatars in the instance. Logs show a null reference in PhysBoneManager...”
I wonder if PhysBones being disabled at load might contribute to that global failure in some edge cases — though again, I don’t have enough evidence to say for sure.
Thanks for reading. Please let me know if anyone has more data on this or if there’s something I can test on my end. I'd be happy to help however I can.
Errorvator
For me, all physbones across all avatars in the instance are broken, and I haven't been able to un-break them yet.
The game was fine for about 30 minutes before the bug started.
My log is filled with this line that might be related
2025.07.17 23:47:00 Error - Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
at UnityEngine.Component.GetComponentsInChildren[T] (System.Boolean includeInactive) [0x00000] in <00000000000000000000000000000000>:0
at VRC.Dynamics.PhysBoneManager.OutputShortDebug () [0x00000] in <00000000000000000000000000000000>:0
at VRC.Dynamics.PhysBoneManager.ScheduleExecutionJob (Unity.Jobs.JobHandle dependsOn) [0x00000] in <00000000000000000000000000000000>:0
at VRC.Dynamics.VRCAvatarDynamicsScheduler.PreScheduleAvatarDynamics (System.Boolean finalizeImmediately) [0x00000] in <00000000000000000000000000000000>:0
Edit: did some additional testing.
* Can repro on both open-beta and live
* Doesn't happen in instances with only a few people
* Still happens with logs turn off
RuneFox237
A friend of mine encountered this but or a similar one to it yesterday. Their physbones stopped working locally for that specific avatar and would only work when a specific gesture was made. All physbones seem to work correctly on remote. Best guess as to the cause might've had something to do with a tongue physbone or something.
Resetting the avatar seems to have fixed the issue for that avatar and we have not been able to get the bug to happen again though.
peacefulranger
Yes some of my avatars do the same thing as yours that whatever they did in this update they need to fix
peacefulranger
Yeah a few of my avatars are the same
1TheBlueWii1
From my testing, this issue happens locally. Apparently the physbones simulate just fine for other players.
Apparently loading an avatar with certain physbones disabled on load will trigger this bug.
Temporary workaround is to enable the physbones when the avatar loads in (such as having an empty animation cell in the animator be the default) then transition to the animations that disable the bones when "TrackingType" > 2.
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