Typically users report seeing this when they are using the Sword & Shield Motion Pack or Archery Motion Pack. In either case, the issue has always come down to a missed step in the setup process.
The documentation for the packs describes a couple of steps:
- Import the asset
- Download the animations from Mixamo
- Import my meta files from the .zip I include
Typically users forget to import the .meta files from the ‘Extras\AnimationMeta.zip’ file. This is critical because Unity stores all the animation meta-data in these .meta files. Without them, the animations aren’t setup correctly… including their unique IDs.
To solve the issue, follow the download and setup steps in the documentation. I also have videos that walk you through the process step-by-step.
Below are examples using the Sword & Shield Motion Pack: