Open Xcode
Select your project
Find the 'General' tab (located within the same tab list as Build Phases, Build Settings etc)
Scroll down to the 'Embedded Binaries' section.
In the list you'll see that TNSCore.framework is in the list multiple times.
Remove the duplicates using the '-' button until there is just one.
Rebuild and hopefully if there are no other duplicates in that list you should have a successful build