You can build via commandline to get past this issue.
/Users/Shared/EpicGames/UE_4.16/Engine/Build/BatchFiles/RunUAT.sh BuildCookRun -nocompileeditor -nop4 -project=/Users/username/project/project.uproject -cook -stage -archive -archivedirectory=/Users/username/Desktop/Build -package -clientconfig=Shipping -ue4exe=UE4Editor -clean -compressed -pak -prereqs -distribution -nodebuginfo -targetplatform=IOS -build -CrashReporter -utf8output