When I go to:
Xcode -> Preferences -> Downloads
I have the following screen:

I am having the following error, after I it has downloaded the iOS 6.0 Library:
Installation path,
/Users/user/Library/Developer/Shared/Documentation/DocSets/com.apple.adc.documentation.AppleiOS6.0.iOSLibrary.docset,
points to a folder that does not look like a valid documentation set
for updating.
What could be done?
My Xcode 4.5 (4G182) downloaded and installed using App Store, refers to the docs as a Documentation Set, not a library:
which has a higher version number than your iOS 6.0 Library.