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Fixed in 2019.2.X

Fixed in 2018.3.X, 2019.1.X



Found in



Issue ID




[iOS] UnitySendMessage is not working on Simulator when trying to login to FacebookSDK



To reproduce:

1. Download attached project "" and open in Unity
2. Open "SampleScene" scene
3. In Player Settings change Target SDK to Simulator SDK
4. Build for iOS
5. Deploy the Xcode project to Simulator
6. Once the Project is running in the Simulator, press the Button on the screen
7. Observe that Xcode throws two Messages and Crashes:

dyld: lazy symbol binding failed: Symbol not found: _UnitySendMessage
Referenced from: /Users/unity/Library/Developer/CoreSimulator/Devices/CF9F69C3-CB01-4626-8B17-54EB714815B3/data/Containers/Bundle/Application/CF63CA6B-336A-41B3-A0A2-7BA8E26BADB1/
Expected in: flat namespace

dyld: Symbol not found: _UnitySendMessage
Referenced from: /Users/unity/Library/Developer/CoreSimulator/Devices/CF9F69C3-CB01-4626-8B17-54EB714815B3/data/Containers/Bundle/Application/CF63CA6B-336A-41B3-A0A2-7BA8E26BADB1/
Expected in: flat namespace

- From Unity 2018.3.0a1 to 2018.3.0a4 when pressing the Button in Simulator, Player crashes because of Shaders and other stuff
- This issue happens in on line 101

Tested with:
- iPhone 7 Plus, iOS: 12.0 - Not Reproduced
- iPhone X, iOS: 11.3.1 - Not Reproduced

Reproduced on Unity 2018.3.0a5, 2018.3.10f1, 2019.1.0b8 and 2019.2.0a9
Not reproduced on Unity 2018.2.20f1
Regression on Unity 2018.3.0a5

Comments (3)

  1. siamon

    Mar 27, 2019 21:28

    (since we can't "vote" on this anymore as it is marked as fixed)

    same issue here, needless to say everything works on actual device....
    stuck in the facebook review because of this.

    any chance we can get 2018.3 patch ?

    unity 2018.3.8f1 , facebook sdk: 7.15.1

  2. michael_looply

    Mar 27, 2019 20:55

    This issue prevents developers from submitting mobile apps to Facebook App Review; any mobile projects that require Facebook permissions outside of basic profile information are blocked on this.

    Is there a workaround available and/or is this fix portable to a 2018.3 patch? Shipping the fix in 2019.2, which is still in alpha, would cause an unreasonably long delay for developers that need to submit to Facebook App Review.

    Forum thread from January with several developers stating that their reviews are blocked for reference:

  3. charlie_sbg

    Mar 25, 2019 15:07

    Tested with 2019.2.0a9. Failed.

    result: the bug still exists in iOS simulator when initializing facebook. The fatal error is "dyld: lazy symbol binding failed: Symbol not found: _UnitySendMessage "

    expected result: game would have loaded in iOS simulator and successfully called to SendMessage.

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