How to reproduce:
1. Create a new Unity project with version 2018.1.9f1
2. Load the project with version 2018.3.0a5
3. Observe the errors in the console as well as the Scene View camera not functioning

Expected result: The Scene View camera can be moved
Actual result: The Scene View camera cannot be moved

Reproducible with: 2018.3.0a4, 2018.3.0a5
Not reproducible with: 2017.1.0a1, 2017.1.5f1, 2017.2.3p1, 2017.4.7f1, 2018.1.9f1, 2018.2.0f2, 2018.3.0a3, 2018.3.0a6, 2018.3.0a7

Notes: The Scene View Gizmos also don't seem to appear once the project is loaded. The issue only occurs the first time the project is loaded in the 2018.3 versions where the problems happen