You don’t need to use ‘-ObjC’ for other linker flags since 4.11. At UnrealEngine/Engine/Source/Programs/UnrealBuildTool/IOS/IOSToolChain.cs line 488, you can see ‘Result += " -ObjC";’. Don’t waste you time like me 
You don’t need to use ‘-ObjC’ for other linker flags since 4.11. At UnrealEngine/Engine/Source/Programs/UnrealBuildTool/IOS/IOSToolChain.cs line 488, you can see ‘Result += " -ObjC";’. Don’t waste you time like me