With the AnimatedShadow script, the SetShadow method seems to be creating some issues on WebGL builds of our app. When we try to pop a modal, nothing happens. On top of that, it creates an infinite loop of null references that all point to that function.
The fix I found was to add in
#if UNITY_WEBGL
instant = true;
#endif
just before the
if (Application.isPlaying && !instant) {
EDIT:
I've found that the culprit lies in the
TweenManager.TweenFloat
function. When displaying or hiding a dialog, that function is called to handle animations, and in both cases avoiding it and doing the assignment directly allows dialogs to show and hide on WebGL. I've not gone deeper to see what exactly in it could be causing the issue.