Which UrbanAirShip version will be compatible with Mono 5.4.1 in Xamarin.Forms?


I am trying to implement UrbanAirship in our Xamarin.Forms project. Currently I just want to implement for iOS. I have tried with UrbanAirship and UrbanAirship.portable version 5.0.2. But I am getting following error during building in AppCenter.

MTOUCH : error MT2101: Can’t resolve the reference ‘System.Void ObjCRuntime.BlockLiteral::SetupBlockUnsafe(System.Delegate,System.Delegate)’, referenced from the method ‘UrbanAirship.UAAction UrbanAirship.UAAction::Action(UrbanAirship.UAActionBlock)’ in ‘Xamarin.iOS, Version=, Culture=neutral, PublicKeyToken=84e04ff9cfb79065’. [/Users/vsts/agent/2.131.0/work/1/s/Source/AsianD8/iOS/MyProject.iOS.csproj]


System info:

Visual Studio 2017 Enterprise


Mono version is 5.4.1.


Note: If we remove UrbanAirship DLLs, it builds successfully.

Can anybody please suggest me why I am getting above error and how to resolve it?

If it is issue of compatibility of Mono and UrbanAirship version, can anybody please suggest me which version I should use for Mono version 5.4.1?


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  • Prakash,

    I just wanted to check, does this same error occur when you build the app in Visual Studio without AppCenter?

  • In visual studio it builds fine.

  • Prakash,

    You may wish to consider just building the project out in Visual Studio rather than through AppCenter. It doesn't look like AppCenter plays nicely with other third-party SDK right now.

    Do you happen to know if using the Sample app that AppCenter provides in their github repo produces any better results?

  • Hi Michael,

    Well, I need to build success on AppCenter also. That is must. Anyways, currently I have degrade to UrbanAirship version 4.6.4 and it builds successfully on AppCenter as well.

    Can you please let me know what can be cause?

    One more thing: With UrbanAirship 5.0.2, I always get ChannelID using "UAirship.Push().ChannelID". But in case of version 4.6.4, sometimes I don't get ChannelID using "UAirship.Push.ChannelID".


    Please suggest

  • Prakash,

    Just to make sure, are you using the latest version of Mono and Visual Studio and AppCenter? Have you tested by updating to Mono 5.8.1?


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