# Help callback failed

**URL:** <https://ask.vrchat.com/t/help-callback-failed/44338>\
**Category:** Help!\
**Tags:** unity\
**Created:** [June 5, 2025, 9:32pm UTC](https://ask.vrchat.com/t/help-callback-failed/44338 "2025-06-05T21:32:14Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![MayuSamaDesu](https://yyz1.discourse-cdn.com/vrchat/user_avatar/ask.vrchat.com/mayusamadesu/32/28602_2.png) [@MayuSamaDesu](https://ask.vrchat.com/u/MayuSamaDesu)\
**Post date:** [June 5, 2025, 9:32pm UTC](https://ask.vrchat.com/t/help-callback-failed/44338/1 "2025-06-05T21:32:14Z")

</div>

The VRCSDK build was aborted because the VRCSDKPreprocessAvatarCallback ‘LockMaterialsOnUpload’ reported a failure.

Failed to build the Avatar, check logs for more details  
UnityEngine.Logger:Log (UnityEngine.LogType,object,UnityEngine.Object)  
(wrapper dynamic-method) UnityEngine.Debug:UnityEngine.Debug.LogError\_Patch1 (object,UnityEngine.Object)  
VRC.Core.Logger:LogError (string,string,UnityEngine.Object)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_143:MoveNext () (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:2920)  
System.Runtime.CompilerServices.AsyncVoidMethodBuilder:Start\<VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_143\> (VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_143&)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder:BuildError (object,string)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_135:MoveNext () (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:2672)  
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1\<System.Exception\>:Start\<VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_135\> (VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_135&)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder:HandleBuildError (System.Exception)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_133:MoveNext () (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:2647)  
UnityEngine.UnitySynchronizationContext:ExecuteTasks ()

Loaded data for an avatar we do not own, clearing blueprint ID  
UnityEngine.Logger:Log (UnityEngine.LogType,object,UnityEngine.Object)  
(wrapper dynamic-method) UnityEngine.Debug:UnityEngine.Debug.LogError\_Patch1 (object,UnityEngine.Object)  
VRC.Core.Logger:LogError (string,string,UnityEngine.Object)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder:ClearAvatarData (VRC.Core.PipelineManager) (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:1677)  
VRC.SDK3A.Editor.VRCSdkControlPanelAvatarBuilder/d\_\_98:MoveNext () (at ./Packages/com.vrchat.avatars/Editor/VRCSDK/SDK3A/VRCSdkControlPanelAvatarBuilder.cs:1556)  
System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1<VRC.SDKBase.Editor.Api.VRCAvatar>:SetException (System.Exception) VRC.SDKBase.Editor.Api.VRCApi/<GetAvatar>d__31:MoveNext () (at ./Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCApi.cs:575) System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1\<VRC.SDKBase.Editor.Api.VRCAvatar\>:SetException (System.Exception)  
VRC.SDKBase.Editor.Api.VRCApi/d\_\_17`1<VRC.SDKBase.Editor.Api.VRCAvatar>:MoveNext () (at ./Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCApi.cs:378) System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1\<VRC.SDKBase.Editor.Api.VRCAvatar\>:SetException (System.Exception)  
VRC.SDKBase.Editor.Api.VRCApi/d\_\_16`2<object, VRC.SDKBase.Editor.Api.VRCAvatar>:MoveNext () (at ./Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCApi.cs:341) System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1\<System.ValueTuple`2<VRC.SDKBase.Editor.Api.VRCAvatar, System.Net.Http.HttpResponseMessage>>:SetException (System.Exception) VRC.SDKBase.Editor.Api.VRCApi/<MakeRequestWithResponse>d__15`2\<object, VRC.SDKBase.Editor.Api.VRCAvatar\>:MoveNext () (at ./Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCApi.cs:332)  
UnityEngine.UnitySynchronizationContext:ExecuteTasks ()

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<div class="post-metadata">

**Author:** ![PrettyLoved](https://yyz1.discourse-cdn.com/vrchat/user_avatar/ask.vrchat.com/prettyloved/32/28602_2.png) [@PrettyLoved](https://ask.vrchat.com/u/PrettyLoved)\
**Post date:** [September 1, 2025, 11:08pm UTC](https://ask.vrchat.com/t/help-callback-failed/44338/2 "2025-09-01T23:08:17Z")

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Did you ever get this fixed?