not able to add core data file to my existing project(version control issue)…?

Programming for ios: not able to add core data file to my existing project(version control issue)…? on newest questions tagged ios – Stack Overflow

I have application with iOS Deployment Target 4.0, now I want to add Data Model file lying under iOS-Core Data.But when I try to add this file into my project below message alerted to me…!?!

“The operation could not be performed because the file is not under version control.”

I try this with test project, in which I create one small project and after that I add this file, but that have no issue
plz help

source: http://stackoverflow.com/questions/11186534/not-able-to-add-core-data-file-to-my-existing-projectversion-control-issue
Programming for ios: programming-for-ios