How to reproduce:
1. Open the attached "PlayerInput" project
2. Open the "SampleScene" Scene
3. In the Hierarchy select the "GameObject" GameObject
4. In the Inspector press the "Create Actions..." button, found in the Player Input Component
5. Press "Save" when the "Create Input Actions Asset" window opens

Expected results: No errors are thrown
Actual results: The "NullReferenceException" error is thrown in the Console

Reproducible with: 1.0.0-preview.7, 1.1.0-preview.1 (2019.4.10f1, 2020.1.6f1, 2020.2.0b3)
Not reproducible with: 0.1.2-preview, 1.0.0-preview.6 (2018.4.27f1, 2019.4.10f1, 2020.1.6f1, 2020.2.0b3)

Notes:
- The Action is still created, it's just not automatically added to the Actions slot and the error is thrown
- The created Action can be added to the Player Input without any issues