Troubleshooting
Cats shows errors in a popup titled Report: Error, or in Blender’s status bar. Here are the ones people run into most, with the fix.
Model and mesh errors
Section titled “Model and mesh errors”No meshes found!
Cats only counts meshes that are parented to the armature. A mesh that sits next to the armature in the Outliner, but not under it, is ignored. Select the mesh, then the armature, press Ctrl + P and pick With Empty Groups or Object, depending on whether it already has weights.
Fix MMD Model says the same thing in its own words: No mesh inside the armature found!
Your Objects/ Meshes are not Single User
Two objects share the same mesh or armature data, usually after duplicating with Alt + D. Select all objects, then run Object > Relations > Make Single User > Object & Data, and try again.
Rigify and Metarig armatures are not supported
Fix MMD Model refuses rigs made with Rigify, detected by the name metarig or bones starting with DEF-, MCH- or ORG-. Use a Rigify-to-Unity add-on to convert the rig instead. If your rig is not a Rigify rig, rename the bones and the armature so they do not use those names.
The following bones were not found
Shown at the end of Fix MMD Model when some main bones, such as a leg or the neck, could not be identified. The fix still completes. Rename the missing bones by hand to the standard names (Left leg, Neck and so on) and check the hierarchy. If the model is unmodified, the upstream project welcomes reports so they can support it.
Import errors
Section titled “Import errors”XPS Tools / Source Tools / VRM Importer is not installed or enabled!
Cats relies on separate add-ons for these formats. Click the download button in the dialog, install the add-on in Edit > Preferences > Add-ons, enable it, and import again.
The FBX file version is unsupported!
The FBX is too old for Blender’s importer. Convert it to a newer FBX version with a tool such as Autodesk FBX Converter.
Translation errors
Section titled “Translation errors”Could not connect to Google / banned from Google Translate temporarily
Cats translated what it could with its built-in dictionary, but Google refused the rest, often after many requests in a row. Wait a while and click Translate again: only the missing names are sent. Check that Blender is allowed to go online.
Export warnings
Section titled “Export warnings”The warnings Cats shows before exporting are advice, not errors: you can click Continue to Export. They match what VRChat uses to rank avatar performance. See the table in Export Model.
Broken shapekeys! is the exception: VRChat refuses to upload an avatar with those shape keys. Delete them, or try Repair Broken Shapekeys in Other Options.
Eye tracking and visemes
Section titled “Eye tracking and visemes”Eye tracking will not work unless the bone hierarchy is exactly as following
Legacy eye tracking: the chain must be Hips > Spine > Chest > Neck > Head, the armature named Armature and the eye mesh Body.
Please select the correct mouth shapekeys instead of “Basis”!
Visemes: pick shape keys that actually open the mouth.
Messages that look like code
Section titled “Messages that look like code”Some messages show up as raw keys, such as VisemePanel.error.noShapekeys or RemoveDoubles.error.failed. That means the English text is missing from the add-on’s translation file. The key usually says what happened: here, the mesh has no shape keys, or removing doubles failed.