CODEWITHSUNDEEP
unity-game-engineeventsmenu
Robin King
Robin King

Reputation: 387

After updating Unity, a second EventSystem is created on Run

I just updated from Unity 2019.3.13f1 to 2021.3.6f1 mid project. Not ideal I know, but I was advised to by Unity Support in order to add the IAP package. After the update, on running my launch scene, I get this error:

There are 2 event systems in the scene. Please ensure there is always exactly one event system in the scene

It turns out, a second EventSystem object is being created on running, which hadn't been the case before the update. At first, I just disabled the one in the hierarchy, which solved the problem as the second EventSystem then didn't conflict. However, when the game goes to a second scene and then returns to the initial scene, the duplicate EventSystem is not created, meaning that the menus don't get any input!

Can anyone advise?

Upvotes: 2

Views: 1301

Answers (1)

Robin King
Robin King

Reputation: 387

This forum post (https://forum.unity.com/threads/upgrade-to-2020-lts-creating-duplicate-eventsystem.1098133/) detailed the same problem.

I have tracked this down to calling Advertisement.Initialize. If I call that while running in the Editor; then it creates a new EventSystem. I am not sure why. It doesn't seem to matter if I pass true or false for the testMode value.

The poster there solved it by surrounding the Initialising line with #if !UNITY_EDITOR. However I wanted to be able to see the adverts testing in the editor - so I added this code, after Advertisement.Initialize(_gameId, _testMode, this):

var es = FindObjectsOfType<EventSystem>();
if (es.Length > 1)
{
   for (int i = 1; i < es.Length; i++)
   {
      Destroy(es[i].gameObject);
   }
}

This seems to have fixed the problem.

Upvotes: 1

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