"Unknown transform context menu index 8" error is thrown on resetting the transform component of any game object.

Steps to repro:
1. Create a new Project.
2. Select the Main Camera.
3. In the Inspector > Reset Transform component.

Actual Result:
Unknown transform context menu Error is thrown in the console.

Expected Result:
Timeline window should be opened.

Reproducible in:
2020.1.0a7.

Working Fine in:
2020.1.0a6, 2019.3.0b5

Environment:
Windows & Mac 10.14.

Stack trace:
Unknown transform context menu index 8