FBX import problems in 2025

In my games I use blender for FBX export and import in Unity.

I’ve figured out how to import the FBX in Unity with correct scale, rotation etc.

The problems arise when I start tinkering with animations that are included in the FBX which causes breaking results in Unity and having to delete and reimport the FBX in Unity, thus losing all references of the animations in Animator, field references etc.

Long story short, after you import an fbx file in Unity, commiting changes in FBX animations like editing animations, removing animations or adding animations will result in a variety of undesired behaviour like animations not importing, broken animations, I even encountered assigning an animation in animator and ended having another animation of the same FBX play instead.

I don’t know if there are serious technical limitations or just plain indifference that makes the fbx import malfunction. But I’m sure it is not rare for someone to want to edit a character’s animations or add more animations and not be able to safely do so.

I did my search and the most popular solutions suggested included either delete the FBX (out of the question) or keep separate files for the animations (also not an acceptable solution because i may make additions to the 3d model e.g. a weapon, an accessory etc).

So, here I am, posting out of despair, because every time I want to make changes and replace the FBX, I have to reimport and reassign all the animations, hoping I’m not forgetting something. Not very productive and certainly, not very pleasant.

I hope someone has to offer a better approach or at least a speckle of hope that the issue is known and a fix is scheduled some time in the near future.

This is not a common issue for experienced artists. But people have been complaining about this for as long as Unity exists. This tells me its entirely a workflow issue. The Internet can give you a helping hand with some tutorial that goes through all the steps of importing and updating FBX with animations.

For sure, there are some quirks revolving around importing or updating any sort of extern asset but once you figured those out, you’ll never make that mistake again. The best course of action is to create a minimal example that exhibits the issue, then tweak whatever you think could cause the issue until you figured it out.

A few common mistakes people make:

  • Not directly overwriting the FBX file under /Assets (eg Delete file first, then Save or Rename new file will break references as will drag & drop the FBX file into the editor since that creates a copy) see this thread
  • Renaming objects or animations in Blender after you started referencing them in Unity
  • Incorrect FBX export settings in Blender or incorrect FBX import settings (there’s guides and best practice videos for these)
  • Doing one-time only setup steps every time you make an update, like creating the Animation Avatar or extracting materials
  • FBX as binary/text … one of these is more compatible than the other but I don’t recall which

Kurt has linked a couple of these threads together.

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