Downgrade of iTunes 11 to 10.7 = error message (-42408)

Question

So I downloaded the latest version of iTunes and immediately regretted it. I then went about reinstalling 10.7 by downloading it from Apple's website and then deleted 11. I replaced the new itunes library with the latest 'previous' version from the itunes folder.
So 10.7 is up and running again but now I get 2 error messages every time I open it.
One says 'An unknown error occured (-402408)' then one appears immediately after saying 'We could not complete your itunes store request. An unknown error occured (-402408). There was an error in the iTunes store. Please try again later'
After I click these away iTunes opperates normally.
I'm sure these error messages are related to my cut and paste way of downgrading itunes but how do i stop the errors from occuring? Is there another file i need to delete/modify/replace?
I really dont want to have to upgrade to 11, I can't stand the new layout that they for some reason are forcing you to have.
Any help would be hugely appreciated,
Thanks,
Jack
Running OSX 10.6.8 on a macbook pro.

Answer 1

=Downgrading from iTunes 11 to iTunes 10.7=
You may be able to go back with Time Machine but this may involve restoring other items too (https://discussions.apple.com/message/20441404).  Alternatively:
Back up your computer first, in case the unexpected happens.
Get iTunes 10.7.  Apple does not keep many old versions on its web site.  I always install iTunes by downloading the installer and then keep it on my archive drive so I can have access to old versions.  This one is no longer openly linked on Apple's site:
iTunes 10.7 for OS X  http://appldnld.apple.com/iTunes10/041-7195.20120912.d3uzQ/iTunes10.7.dmg
Replace the iTunes 11 application with iTunes 10.7.  Lion (OSX 10.7) and newer systems have iTunes integrated into the operating system and deleting is a bit more involved.  The two ways I can think of to do this are:
1.  Use the shareware Pacifist utility (http://www.charlessoft.com/) to install iTunes 10.7 including all associated system files..
2. Check this reference on how to delete the iTunes application itself:
Delete iTunes in Mac OS X 10.7 Lion - http://osxdaily.com/2011/09/13/delete-itunes-in-mac-os-x-10-7-lion/
In addition there may be other files that need downgrading too. See the note about error -42408 at the end of this post. You may want to tuck these away somewhere safe until you have completed the installation of iTunes 10.7.  I have not tested this but ideally if newer versions are not found then the installer will put in the old versions. This may include these files in /System/Library/PrivateFrameworks/ which apparently get updated by iTunes 11:
AirTrafficHost.framework
CoreFP.framework
DeviceLink.framework
iTunesAccess.framework
MobileDevice.framework
After replacing the application and associated files using one of the above methods you will have to rescue your old iTunes library from your iTunes > Previous Libraries folder and rename it "iTunes Library.itl" (replacing the existing one in the iTunes folder) because a newer version of iTunes irreversibly updates your library file. Note, this will revert your library to version at the time of the upgrade and you will have to update any changes made since.  See:
https://discussions.apple.com/message/20401436 - turingtest2 11/2012 post on rebuilding empty/corrupt library from previous iTunes library file after upgrade/crash.
iTunes: How to re-create your iTunes library and playlists - http://support.apple.com/kb/ht1451
Other issues:
https://discussions.apple.com/message/20432309 - solution to mobile devices saying they need to be restored after downgrading
If you encounter error-42408:
iTunes: Advanced iTunes Store troubleshooting - http://support.apple.com/kb/TS3297 > Specific Conditions and Alert Messages: (Mac OS X / Windows) - including specific error codes.
Alternatively, check https://discussions.apple.com/message/20441424 which requires you have a Time Machine backup (though possibly if you remove the newer version of these files old ones may be installed with the iTunes 10.7 installer - untested).