The command has a known issue (PowerShell/PowerShell#8211). Suggested workaround is using a custom function to remove files/directories synchronously: https://stackoverflow.com/questions/53553729/cannot-remove-item-the-directory-is-not-empty/53561052#53561052

I like .ply, it's an easy format that supports vertex colors! .ply files are often used for point clouds, so it could be good to consider point cloud rendering when importing .ply files as well.

Might be able to find a nice library for this on here:
https://github.com/nothings/single_file_libs

Environment

Windows 10
Unity version 2017.4.3f1
Downloaded the repository on 10/05/2019
Visual Studio Version 2017
HoloLens 1

Steps to reproduce

1. Build the Unity scene M2MqttUnity_TestXR without any modifications to the code or anything.
2. Once the build is successful, open the M2MqttUnity.sln from Visual studio 2017
3. Set settings to Release, x86 and Device
4. Start Debug