I am using Unity version 2019.2.6f1.
This is the error that I get when I import Project Tiny:
Library\PackageCache\com.unity.tiny@0.16.1-preview\Unity.Serialization.Properties\SerializedObjectViewPropertyBag.cs(192,33): error CS0246: The type or namespace name ‘ICollectionElementGetter<>’ could not be found (are you missing a using directive or an assembly reference?)