Linker command failed with exit code 1 (duplicate symbol)

Question

I developing a game in Unity and I have used Admob, Facebook and GameCenter in it. It was working fine on iOS until I have added the OpenIAB for in-app purchase, though it works

Answer 1

Look up in your project for:

MakeStringCopy

And make sure it exists (if exists) only once. If it appears more then once, rename one (make sure to rename it where it being called as well) and try to build again.