xcode 4.5 some install Error

Question

xcode 4.5 OSX 10.8 CoreLibrary(529mb) install error like this.

"Failed to install documentation for OS X 10.8 Core Library" Installation path is /User/*/Library/Developer/Shared/Documentation/DocSets/com.apple.adc.documentation.AppleOSX10_8.Core...,points to a folder that does not look like a valid documentation set for updating

And simulator 6.0 lunching time is very slow(rather than simulator 5.0).

My mac os is "Mountain Lion".

I already try reinstalling but not working.(use AppCleaner)

Answer 1

I found a previous unfinished download left files to be deleted.

1. Exit Xcode.
2. Go to ~/Library/Developer/Shared/Documentation/DocSets
3. Remove the entire com.apple.adc.documentation.AppleOSX10_8.CoreReference.docset
4. Open Xcode and restart the download and install process.