I need to install Xcode 4.6.2 on Mountain Lion 10.8.5. I got the dimg file from developer.apple.com, and ran it to install. This appeared to work, but when I click the icon in Finder, I get a dialog to install "Device Support." When I click Install, I get a message "An unknown error occurred. See the install log for more details." There is no way to make progress and no relevant message in the log. Please note, I have admin privileges while I do all this.
I have searched this site for similar questions, but all I found was a very similar (identical) problem with Xcode 4.6.2 and Lion 10.7.5 - but there was no answer. (I know that this version of Xcode does work with OS X 10.8.2, so I don't think compatibility is a problem here.