Troubleshooting

Overview

This page summarizes common problems and their solutions when using AITuberKit. We will continue to add typical errors and issues along with their causes and solutions, providing detailed explanations based on specific cases to support smooth operation.

TypeError: _currentFrameNo when loading Live2D models

Symptoms

When selecting a custom Live2D model in AITuberKit, the following error appears and the model does not render.

Unhandled Runtime Error
TypeError: Cannot set properties of undefined (setting '_currentFrameNo')
  at Cubism4InternalModel.updateWebGLContext (...)
  ...

Cause

• This is a known bug in the pixi-live2d-display library family.
• If the model does not have any clipping masks (ArtMesh ▶ Drawing ▶ Generate Mask), the _clippingManager is not created and remains undefined.
• Inside Cubism4InternalModel.updateWebGLContext, this._clippingManager._currentFrameNo = ++frame; is executed, causing a TypeError.
• Additionally, models exported in Cubism 5 format (.moc3 v4) are not compatible with the libraries included in AITuberKit.

Solution

1. Open the model in Live2D Cubism Editor.
2. Select any ArtMesh, then enable Generate Mask in [Inspector] ▶ [Drawing].
3. Select [File] ▶ [Export] ▶ Model(.moc3), and specify the following in the dialog:
   • SDK: SDK for Web
   • Version: Cubism 4.2 (or 4.0/4.1)
4. Place the output folder in public/live2d/model-name/ and reselect model-name.model3.json in AITuberKit.
5. To enable lip-syncing, add LipSync to Groups in model3.json.

Hint

Adding a mask to lightweight meshes like eyebrows or highlights will also resolve the issue. If you want to avoid visual impact, you can create a new invisible small mesh and generate a mask on it.

Quick Reference for Relevant Live2D Settings

Setting Location	Requirements for Normal Operation	Notes
ArtMesh ▶ Drawing ▶ Generate Mask	At least 1 ON	Any part can be used (eyebrows, hair highlights, etc.)
Model Export	Select SDK for Web / Cubism 4.2 or earlier	Cubism 5 format (.moc3 v4) is not supported
model3.json → Groups	Add EyeBlink and LipSync	No error occurs without them, but expressions and lip-sync won't work

If your model renders correctly in AITuberKit after following these steps, you're all set. For Live2D settings, please refer to this page.