how to fix 'unknown type name' errors when adding ZIPArchive for iOS to xcode

Question

i have drag and drop ziparchive to my xcode (xcode version 4.3.2) project,
i have also checked the

"Copy items into destinations group's folder" (if needed)  

and

"Create groups for any added folders"

But i am getting the following errors(see the image attached).
I really dont know how to fix that, whats the problem here?

Answer 1

Have a look at a header that you have written recently. When such errors happen to me it's usually because one of my header files is malformed. Which means that it runs on into other headers that are imported by other classes.