XCode 9 error: UI API called from background thread

I'm trying to install a very simple ARKit app on an iPhone - it is a default Unity scene which goes with ARKit plugin for Unity.
But after successfull installation I can't run the app:


- I see "Waiting for editor connection..." text on the iPhone screen
- I see multiple warnings and one error in the XCode 9: "UI API called from background thread", "UIApplication delegate must be used from main thread only".

Here are the screenshots:


Screenshot-1


Screenshot-2

I'm a very beginner, and I don't know Objective-C yet, but I work with Unity, and according to the tutorials it shouldn't happen.

Why could it happen and how can I fix it?



I would really appreciate your help!

Thank you in advance!


I use:
Free Apple ID Developer Account

Unity 5.6.2f1 (I tried also 5.6.1p1, the same result)

Iphone 7 Plus, IOS 11 (public, free)

Xcode 9 Beta 6

MacBook Pro (Mid 2015)

Did you find a solution for this? I have the same issue.

Same here. 😟

XCode 9 error: UI API called from background thread
 
 
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