Class _NSZombie__GEOTileKeyWrapper is implemented in both ?? and ??. One of the two will be used. Which one is undefined

Question

I have this message while debugging my app:

Class NSZombie_GEOTileKeyWrapper is implemented in both ?? and ??. One of the two will be used. Which one is undefined.

Do you know what is this? And how to fix it?

Answer 1

You can ignore this particular message.

The reason you can ignore it, is because it says:

Class NSZombie_....

Which means that the object to which the message is referring is a dummy object created by Xcode Diagnostics. Read more about Zombies here. The message should not appear if you disable Zombie Objects in your environment diagnostics options.

Answer 2

This happens when you have two implementations of the same class and Obj-c runtime is unable to decide which one to use.