it seems that tiny just focus on runtime, leck the design time, here is the error when i play,is it?

Unity 2020.2.1/ the TinyPhysics
InvalidOperationException: GetSingleton<Unity.Tiny.DisplayInfo>() requires that exactly one Unity.Tiny.DisplayInfo exist that match this query, but there are 0.
Unity.Entities.EntityQueryImpl.GetSingleton[T] () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/Iterators/EntityQuery.cs:745)
Unity.Entities.EntityQuery.GetSingleton[T] () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/Iterators/EntityQuery.cs:1341)
Unity.Tiny.Rendering.UpdateCameraMatricesSystem.OnUpdate () (at Library/PackageCache/com.unity.tiny@0.31.0-preview.24/Unity.Tiny.Rendering/CameraComponents.cs:352)
Unity.Entities.SystemBase.Update () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/SystemBase.cs:413)
Unity.Entities.ComponentSystemGroup.UpdateAllSystems () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:435)
UnityEngine.Debug:LogException(Exception)
Unity.Debug:LogException(Exception) (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/Stubs/Unity/Debug.cs:19)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:440)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:387)
Unity.Entities.ComponentSystem:Update() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystem.cs:113)
Unity.Entities.DummyDelegateWrapper:TriggerUpdate() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ScriptBehaviourUpdateOrder.cs:333)

 

This is posted probably once a week. Use search and the manual states that running in editor is not supported. Use Build & Run with one of the build configurations inside the Build folder.