World/Udon Bugs & Feature Requests

Sometimes, upon joining a world, OnPlayerDataUpdated() fires with infos containing all of the existing keys, but the State on each PlayerData.Info is set to Added instead of Restored. I have not found any rhyme or reason to why this happens, but it seems to be happening more frequently lately. This is happening on whatever client version was recent as of 2025/09/09.

There is an undocumented limit on Network IDs. If you assign a Network ID beyond 10 000 to a PlayerObject its persistence features will break while the UdonBehaviour itself still functions and syncs. ClientSim throws the following error: ran out of player persistence view ids In-game testing results in Removed some Player Persistence metadata that had invalid IDs. errors. Apparently there is a limit of 100 000 for Network IDs in general, its way less likely to hit this, but this also seems undocumented. The difference in limit for PlayerObjects and standard UdonBehaviour objects is confusing and the provided errors don't accurately explain how to solve this issue. The Network ID Utility also does not seem to take this limit for Player Objects into account and does not warn or ensure a lower ID is assigned to the persistent objects. Furthermore, the Network ID Utility crashes on projects with this many Network IDs, but this was already documented here: https://feedback.vrchat.com/sdk-bug-reports/p/network-id-utility-has-massive-performance-issues

The OnAvatarChanged() Udon event is fired when you finish IK calibration, when I dont really think it should be, as you havent actually changed avatars. Ideally, this behaviour would be changed so that OnAvatarChanged does not get called on IK recalibration, and then incase anyone is using it to detect IK Recalibration, maybe add in a event for that specifically

VRCSDK3-WORLD-2021.03.09.13.57_Public Unity 2018.4.20f1 When many Midi Events are received, references outside the buffer range will occur. Log IndexOutOfRangeException: Index was outside the bounds of the array. VRC.SDKBase.Midi.VRCPortMidiInput.Update () (at Assets/VRCSDK/SDK3/Runtime/Midi/VRCPortMidi.cs:71) VRC.SDK3.Midi.VRCMidiHandler.Update () (at <5d3e9f7f72234587a2c25e98f82b4f27>:0)

I'm trying to add shadows to my world Test Pilots and it works fine on desktop mode but in VR I'm getting severe shadow acne. I've attached two images, one showing desktop and one showing VR. I have messed with the following settings (and there are sliders to change them in the world): Near/Far clipping plane Directional light's Bias and Normal Bias None of them seem to help much, so I'm wondering if there's an internal VR setting that has been overlooked that is causing this issue. My settings are as follows: Near: 0.05 (max allowed in VRC) Far: 50000 I realize these settings are extreme, but I can't see a reason why there'd be such a huge difference between VR and desktop. I've uploaded a barebones version of the world for testing at: https://vrchat.com/home/world/wrld_6a5d6107-25a1-4152-9eb2-0b110ae23432/info To see the issue go in VR and either fly up in the air using jump + left trigger OR click on the 'Teleport To Light Control' button and look towards the large grey structure. Note there is a day/night cycle in the world so sun angle may change if you stay too long. Hit the 'Set Day' button at spawn to freeze it. Issue has been observed on Index and Quest 3

This has been broken for a long while, since I can remember, Auto Hold does not work for Oculus, or Index, but does work for Desktop, and (last I checked) Vive.

When a player leaves the instance or enters a station, OnPlayerTriggerExit does not fire for any trigger colliders that they were in. This will break any system trying to count the players in an area. It is known that Unity will not fire OnTriggerExit when either deleting the collider or disabling colliders, but you must move the collider out of the area. Example world: wrld_d3e81903-54d6-4562-a968-2223c368906e World has a blue trigger area and will display when a player enters or exits. There is also a chair in the area. Test case 1: Have two or more players in the room. Have one player enter the area Have that player leave the instance. Note that a player exit trigger message is never displayed. Expected result would be that OnPlayerTriggerExit fires, which would then display the message Test case 2: Have one player enter the blue area. Have that player sit in the chair. Notice that player exit area does not fire. Have the player exit the chair. Notice that player enter does fire and the count is now off by one. Expected result would be that on entering a station (which disables the player collider), Player trigger exit fires.

When adding [UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)] to an udon# class, It will just continue using the last setting. For example if you add [UdonBehaviourSyncMode(BehaviourSyncMode.Continuous)] and then compile, then change it to [UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)] and compile again, you get the expected behavior, and calling SendCustomNetworkEvent() works. If you then change it to [UdonBehaviourSyncMode(BehaviourSyncMode.None)] and compile, then change it to [UdonBehaviourSyncMode(BehaviourSyncMode.NoVariableSync)] and compile again It will continue to behave exactly as if it's still set to None. SendCustomNetworkEvent() does not work. This is on an object that doesn't have any other scripts on it. I haven't tested the case with other scripts. You can look at the debug inspector to confirm that this is what is happening. From the documentation: "NoVariableSync: Enforces that there are no synced variables on the behaviour, hides the sync mode selection dropdown, and allows you to use the behaviours on GameObjects that use either Manual or Continuous sync." It seems like the case where a script using NoVariableSync being used on an object that doesn't have another script on it may have been overlooked. Since I'm updating a script in a prefab I'm releasing from None to NoVariableSync because I want to use network events now, it's not going to work for anyone updating to the new version. I am forced to set it to Continuous. Does anyone know if it makes any difference to bandwidth usage?

ClientSim gathers the "PlayerPersistenceObjects" in ClientSimPlayer.cs before ClientSim removes objects that are tagged EditorOnly. This breaks the ClientSim initialization process, resulting in "_stackedCameraReady" never being set to true. This results in the menu's "ToggleMenu" function failing to close the menu, causing the user being unable to test their scene under this scenario.

[Repro] Empty object with a station, a script that has Interact on it for entering station ala UseStation, and a box collider for interaction. Add an enter and exit transform to the station and move the enter location away from the station's position. Set the station to "Mobile" Player Mobility. Example https://streamable.com/zo4d0i I have attempted with multiple locations for the enter transform and the resulting location varies wildly. Immobile works fine as expected.