Import Troubleshooting #5

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opened 2026-07-20 23:17:48 +00:00 by Yippie223 · 1 comment

Yippie223 commented

2026-07-20 23:17:48 +00:00

After setting up an avatar in Unity, VRC SDK warned me that it was unoptomized, even after using my normal workflow. So I read VCC's Avatar Optimization Tips and set up Blender 5.2 with the Cats Blender Plugin. To bring the Avi to Cats, I used Unity's FBX Exporter with expected results. Then I imported the FBX using Cats and got an error message and a very messy result.

Not sure if this was iust a poor interaction with the FBX Exporter- so I tried a few different settings but it seems to consistently import in the same way.

PS: I'm self-taught in Unity and Blender, so its entirely possible I just borked some settings or missed something simple.
Thank you for your time!

After setting up an avatar in Unity, VRC SDK warned me that it was unoptomized, even after using my normal workflow. So I read [VCC's Avatar Optimization Tips](https://creators.vrchat.com/avatars/avatar-optimizing-tips/) and set up Blender 5.2 with the Cats Blender Plugin. To bring the Avi to Cats, I used Unity's FBX Exporter with expected results. Then I imported the FBX using Cats and got an error message and a very messy result. Not sure if this was iust a poor interaction with the FBX Exporter- so I tried a few different settings but it seems to consistently import in the same way. PS: I'm self-taught in Unity and Blender, so its entirely possible I just borked some settings or missed something simple. Thank you for your time!

Screenshot 2026-07-20 183802.png

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Screenshot 2026-07-20 183719.png

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Yusarina commented

2026-07-21 20:36:40 +00:00

Owner

The crash is happening entirely inside Blender's own FBX importer, before Cats even gets to touch anything, so there's nothing we can do about it on our end.

Specifically it's failing on the skeleton's bind pose (Hips), which is a known thing with Unity's exporter when the rig is set to Humanoid it can mangle/duplicate the root bones on export and other tools' FBX importers (Blender included) choke on it.

Best fix if you've still got the original Blender/FBX file from before it went into Unity, use that instead, that's the normal Cats workflow anyway (optimize before Unity, not after). If you don't have that, try switching the rig to Generic instead of Humanoid before re-exporting from Unity, or grab a third-party exporter like Better FBX Exporter from the asset store, it tends to produce way less broken files than Unity's built-in one.

Unity's FBX Exporter is actually terrible and does some weird things which the Blender importer chokes on, this is not a Cats issue, the error is not related to Cats, Cats just calls Blender's importer with a couple default settings and none of those touch what's failing here. The crash is happening entirely inside Blender's own FBX importer, before Cats even gets to touch anything, so there's nothing we can do about it on our end. Specifically it's failing on the skeleton's bind pose (Hips), which is a known thing with Unity's exporter when the rig is set to Humanoid it can mangle/duplicate the root bones on export and other tools' FBX importers (Blender included) choke on it. Best fix if you've still got the original Blender/FBX file from before it went into Unity, use that instead, that's the normal Cats workflow anyway (optimize before Unity, not after). If you don't have that, try switching the rig to Generic instead of Humanoid before re-exporting from Unity, or grab a third-party exporter like Better FBX Exporter from the asset store, it tends to produce way less broken files than Unity's built-in one.

Yusarina closed this issue

2026-07-21 20:36:40 +00:00

Yusarina added the

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not cats related

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2026-07-22 13:09:27 +00:00