Reproduction steps:
1. Open the attached “bug-report.zip” project
2. From the Project Window select “Character.psb”
3. Click on “Open Sprite Editor” in the Inspector
4. In the Sprite Editor window, switch the dropdown from “Sprite Editor” to “Skinning Editor”
5. Select “Auto Geometry” on the right side menu
6. Click on the “Visibility” button at the top to open the Visibility menu
7. Select “Sprite” and hide any of the Sprites
8. In the Geometry window click “Generate For All Visible” button
9. Observe the Console and the Editor

Expected result: The geometry gets generated
Actual result: “ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.” is thrown and Editor hangs indefinitely

Reproducible with: 2021.3.43f1, 2022.3.45f1, 6000.0.18f1

Reproducible on: Windows 11
Not reproducible on: No other environment tested