Hi, I haven't installed OSX 10.13 yet since I heard there are issues with Unity:
https://forum.unity.com/threads/unity-and-macos-10-13-high-sierra.474527/I'm not able to repro the problem in 2017.2.0f3 in OSX 10.12/Windows 10.
It's possible you're running into the OSX problems in that post. I believe there are workarounds listed that you could try...
Also, when did you download the samples?
The unitypackage was updated a little while ago. Try downloading again to make sure you have the current version.
If none of that works let me know. It could be an issue with the patch version of Unity. Patch versions can be unstable or break things since they haven't been fully tested by Unity. We generally don't test on every patch version released. But if none of the above helps, I'll download 2017.2.0p2 and test to see if that's the problem.