Error on test ECS example

[Darth-Carrotpie]

Following the example from readme, an error is thrown every frame:

Exception: This method should have been replaced by source gen.
MagicTween.Core.Systems.SequenceSystem.OnUpdate () (at Assets/Third Party Packages/MagicTween/Runtime/Core/Systems/SequenceSystem.cs:46)
Unity.Entities.SystemBase.Update () (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.ComponentSystemGroup.UpdateAllSystems () (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:723)
UnityEngine.Debug:LogException(Exception)
Unity.Debug:LogException(Exception) (at ./Library/PackageCache/com.unity.entities/Unity.Entities/Stubs/Unity/Debug.cs:17)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:728)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:681)
Unity.Entities.SystemBase:Update() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:723)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:681)
Unity.Entities.SystemBase:Update() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:723)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ComponentSystemGroup.cs:687)
Unity.Entities.SystemBase:Update() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/SystemBase.cs:418)
Unity.Entities.DummyDelegateWrapper:TriggerUpdate() (at ./Library/PackageCache/com.unity.entities/Unity.Entities/ScriptBehaviourUpdateOrder.cs:523)

Needless to say the example does not work.