Hello Peng Han Kum – welcome to the Lightship development community!
Thank you for identifying and reporting the issues you found with the Building with VPS tutorial. We have been able to identify and reproduce the errors on our end, and we’ve informed the team of the issues.
You were correct that in order to compile the ARGameLogic.cs script, you will need to add using System; and using System.Linq; to your script header. Additionally, you will need to add your own prefab GameObject instead of the mushroom. You can add a simple cube prefab for testing purposes.
Also, in the OnSessionStarted() method, be sure to subscribe the OnSessionStarted() method to the Ran event handler using the following line…
session.Ran += OnSessionStarted;
…as this method contains the application’s location service and wayspot anchor service initialization.
As for the pink material floor plane, can you navigate to the PlanePrefab asset, double-click it to open it up and ensure the Plane child GameObject’s material is using the Unlit/PlanefindingGrid shader?
Thank you again for reporting the issues you found, and let us know if you have additional questions.