UnassignedReferenceException: The variable _canvas of ConfirmPurchaseWindow has not been assigned.
You probably need to assign the _canvas variable of the ConfirmPurchaseWindow script in the inspector.
OfficeRiot.Windows.Shop.ConfirmPurchaseWindow.Init () (at Assets/Scripts/Windows/Shop/ConfirmPurchaseWindow.cs:37)
OfficeRiot.WindowsManagement.WindowsController.Init (System.Action callback) (at Assets/Scripts/Management/WindowsManagement/WindowsController.cs:35)
OfficeRiot.Preloader.PreloaderHelper.InitNextController () (at Assets/Scripts/Preloader/PreloaderHelper.cs:119)
OfficeRiot.StatsManagement.StatsController+<InitCoroutine>d__11.MoveNext () (at Assets/Scripts/Management/StatsManagement/StatsController.cs:65)
UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) (at /Users/builduser/buildslave/unity/build/Runtime/Export/Scripting/Coroutines.cs:17)