How to reproduce:
1. Open user-submitted project (New Unity Project (14))
2. Open 'New Controls' control settings
3. Select 'New Control Scheme 1'
4. Select 'Keyboard' device
5. Attempt to add a Binding/1D Axis Composite/2D Vector Composite to New action

Expected result: a Binding/1D Axis Composite/2D Vector Composite is added
Actual result: a NullReferenceException is thrown

Reproducible with Unity versions: 2019.1.8f1, 2019.2.0b7, 2019.3.0a7
Could not test with Unity versions: 2017.4.29f1, 2018.4.3f1(regressed package version incompatible)

Reproducible with package versions: 0.2.8, 0.2.10
Not reproducible with package versions: 0.2.1
Could not test with package versions: 0.2.6(Adding actions which are required for bindings results in another NullReferenceException)

Notes:
Does not reproduce when adding bindings to all devices