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Unity XCode Linker Error

Im having issues building the wikitude example proejct for IOS devices. The project builds fine in Unity.  but wont  build/run from Xcode.

I get the following Linker error

"_OBJC_CLASS_$_MTLRenderPassDescriptor", referenced from:

      objc-class-ref in libWikitude2UnityBridge.a(WTWikitude2UnityBridge.o)

ld: symbol(s) not found for architecture arm64

I think I have followed all the steps correctly and cant progress further, I was hoping someone can shed some light on this issue.


Unity3d version 5.4.2

Xcode 8.3.3


WikitudeNativeSDK framework was added as a Embedded Binary

Have set the Camera desciption

Minimum IOS is 9.0

Have set Bitcode to NO

Hello Glenn,

Please make sure that you follow all the steps described here. Did you also add all the iOS system frameworks that the Wikitude SDK requires? You can find a lost of all Frameworks that you need to link in the iOS Setup Guide here. Alternatively, you can compare project settings with the Wikitude SDK example application and yours.

Finally, this forum post here might also help you.



While im checking the steps. I have 2 further questions.

1. What is the minimal version of Xcode required to build the xCodeProject with?

We have a machine using 7.3 that immediately gives a "an unkown error has occured" notification while trying to build.

While a machine with 8.3 gets to the point of the earlier mentioned issues.

2. do you mean that the whole ios setup is needed in addition to the Unity Setup? or just as a refrence, since most of what is being described in the IOS setup (like adding frameworks. i.e "CoreMotion.framework, etc") is already handled automatically.

Hi glenn,

I hope to help with the following answers:

1) We don't have required Xcode version for our SDK releases. We follow Apples recommendation to always use the latest developer tools.

2) Unity already adds most system frameworks automatically, but you should check yourself if all Wikitude SDK related frameworks are included. You linker error strongly refers to a missing Metal.framework. Can you please make sure that you have this as a 'Link Binary With Libraries' entry listed.

If it still does not work for you, can you please send me screenshots of your Xcode project target overview page ('Link Binary With Libraries' section) and your `About Xcode` dialog?

Best regards,


Hey Andreas,

I have been able to get the project running on a diffrent Mac, as far as I know I didn't do anything diffrently then before, besides unpacking the UniyPackage on the Mac itself and then building that unity project.

Before I had build the xCode project on my windows machine, and send the xcode to the Mac to put it on the device.  I am not sure if this actually was the issue, and I likely wont have the time to investigate this atm. But just in case I thougth I should mention it.

Anyway,  Im able to use wikitude on Iphone now. Thanks for your responses.



Hi glenn,

Thx for sharing your solution/experience!

In case you have any other question related to the Wikitude SDK/Unity package, don't hesitate to ask!

Best regards,


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