Xcode 4.3.3 をインストールしました。Xcode 3.2.6を使用する前。Xcode 3.2.6 で作成したアプリを iPhone 4S にインストールしようとすると、次のエラーが発生します。
Ld /Users/me/Library/Developer/Xcode/DerivedData/MyApplication-ezwzjyiebhnsmsgehafwnegjidhu/Build/Products/Debug-iphoneos/MyApplication.app/MyApplication normal armv7
cd "/Users/me/Desktop/Old Data/desktop/UpdatedApp/MyApplication"
setenv IPHONEOS_DEPLOYMENT_TARGET 5.1
setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk -L/Users/me/Library/Developer/Xcode/DerivedData/MyApplication-ezwzjyiebhnsmsgehafwnegjidhu/Build/Products/Debug-iphoneos -F/Users/me/Library/Developer/Xcode/DerivedData/MyApplication-ezwzjyiebhnsmsgehafwnegjidhu/Build/Products/Debug-iphoneos -filelist /Users/me/Library/Developer/Xcode/DerivedData/MyApplication-ezwzjyiebhnsmsgehafwnegjidhu/Build/Intermediates/MyApplication.build/Debug-iphoneos/MyApplication.build/Objects-normal/armv7/MyApplication.LinkFileList -dead_strip -miphoneos-version-min=5.1 -framework Foundation -framework UIKit -framework CoreGraphics -framework CFNetwork -framework CoreLocation -framework MediaPlayer -framework MapKit -framework MobileCoreServices -lxml2 -lz.1.2.3 -framework SystemConfiguration -framework MessageUI -o /Users/me/Library/Developer/Xcode/DerivedData/MyApplication-ezwzjyiebhnsmsgehafwnegjidhu/Build/Products/Debug-iphoneos/MyApplication.app/MyApplication
ld: library not found for -lz.1.2.3
clang: error: linker command failed with exit code 1 (use -v to see invocation)
なぜこのエラーが発生するのか、どうすれば解決できるのか。前もって感謝します。