Assets/RaycastHit.js(7,27): BCE0023: No appropriate version of 'UnityEngine.Physics.Raycast' for the argument list '(UnityEngine.Vector3, UnityEngine.Vector3, RaycastHit, int)' was found.
looks like you named your class RaycastHit which overrides the RaycastHit class in Unity. Physics.Raycast() doesn't know what to do with your class so it errors out. Rename your class as something else or use UnityEngine.RaycastHit when declaring your variable.