Reproduction steps:
1. Open the attached “IN-99929.zip” project
2. From the Project window, double click on the "m1.anim" to open the Animation window
3. Select any of the keyframes
4. Try to move the keyframe
5. Observe the keyframe and the Console window

Expected result: The keyframe is moved, and no errors are in the Console
Actual result: The keyframe doesn't move, and an “InvalidCastException: Specified cast is not valid.” exception is thrown

Reproducible with: 6000.2.0a9, 6000.2.0a10
Not reproducible with: 2022.3.61f1, 6000.0.48f1, 6000.1.1f1, 6000.2.0a8 (8a36f491c000)

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