Using ClientSim, when a player joins, OnAvatarEyeHeightChanged is invoked with the prevEyeHeightAsMeters parameter passed as the literal integer 0, causing a type mismatch since it is expected to be a float.
Repro:
  1. Create an Udon Program that uses the OnAvatarEyeHeightChanged event.
  2. Use the prevEyeHeightAsMeters for any type-specific externs, like addition.
  3. Test the world using ClientSim and you will get an exception.
This bug was introduced in 3.6.0 and I have gone ahead and created a simple PR addressing it: