Multi-selecting items in the Project tab throws error in the console. Selection is not displayed in the inspector.

Steps for reproduction:
1) Open the attached project below or create a new scene and add some files in the Project folder
2) Select multiple items in the Project tab
3) Check the console log and the inspector, items are not displayed
4) Observe the bug

Notes:
- Regression introduced in 2017.1.0b1
- Issue is not reproducible in 2017.1.0a6
- Results are shared with GIFs below (with expected and current outcomes)