1. Open Unity on OSX;
2. Create new project;
3. Add Cube gameobject;
4. In the Inspector click on 'Cube' under 'Cube (Mesh Filter)' component to invoke reference to Project folder (it should be highlighted in yellow);
5. Right click on Unity tray icon and press 'Quit';
6. Click 'Don't save'.

Actual result:
Unity crashes. See attached video.
Regression introduced in Unity 2017.1.0a4.

Last calls in the stacktrace:
#0 0x007fff92eddb5d in objc_msgSend
#1 0x00000101f7252f in WebViewWindow::~WebViewWindow()
#2 0x00000100487254 in CefInstance::Terminate()
#3 0x00000101f725b6 in WebViewWindow::Shutdown()
#4 0x00000101f0bd90 in Application::Terminate()
#5 0x00000101fca04e in -[EditorApplication applicationShouldTerminate:]
#6 0x007fff7bfab420 in -[NSApplication _docController:shouldTerminate:]

Notes:
- Crash might also happen when launching Play mode after invoking reference to Project folder (hard to repro);
- Reproducible in 2017.1.0a4;
- Not reproducible in 2017.1.0a3, 5.6.0f2, 5.5.2p1.;
- Reproducible only on OSX 10.12.3 running GLCore; not reproducible on Windows 10;
- Crash doesn't lead to any data loss (unless crash when entering Play mode).