Q: Availability.h file not found - Xcode 4.6.1 - Objective-C After I updated XCode to 4.6.1 version, when I open a project developed in the last Xcode version, it gives me an error when I run the application, on the #import <Availability.h> (I don't know in which class is that code line). The error I get is: "'Availability.h' file not found". How can I solve this?

A: Problem might be with the Foundation.framework, try to delete the framework in build-phases and add it again to your project.
Once you have added it again, just clean and build your project, it will solve your problem.
If by doing the above does not solve your problem then you will have to re-install xcode I am afraid.

A: at Target->Build Phases-=>Link Binary with Libraries remove Foundation.Framework and add it again
