How to reproduce:
1. Create a new project
2. Change its version control mode to use Perforce (No input is needed, simply changing the mode is enough)
3. In the Hierarchy Window create a new Canvas object
4. In its Inspector Window, right-click the "Graphic Raycaster" component and click "Edit Script"
5. Observe the console window

Expected result: nothing is selected and no errors are thrown
Actual result: the Editor selects an internal UnityEngineUI.dll file and continuously throws nullreference exceptions while it is selected

Reproduced in: 2019.1.0a11, 2018.4.1f1, 2018.3.14f1
Not reproducible in: 2019.3.0a4, 2019.2.0b4, 2019.1.5f1, 2019.1.0a12, 2018.2.21f1, 2017.4.28f1 (On these versions the UnityEngineUI.dll doesn't get selected when trying to edit the component and thus no errors are thrown)

Note: This reproduces with any editor component that is marked as "script"