I have upgraded to Unity 2018.3. Glitch Garden up to this Lesson is working correctly. I have viewed the video for this lesson multiple times and have compared my settings & code to the video. All works except that the Level Lost Canvas does not block clicking the defender buttons. I am able to click them, but cannot place them. Level Lost Canvas in 10 in the Order in Layer. Each button is 7.
Here is the Inspector for the Level Lost Canvas:
My workaround for this issue:
Inset the following code
if (Time.timeScale <= Mathf.Epsilon) { return: }
as the first statement in OnMouseDown() in DefenerButton.cs and DefenderSpawner.cs