i updated itunes and cant launch it anymore
after updating itunes i cant use it at all, its not launching and not reacting
Apr. 2015 Niel post: Re-install iTunes application - https://discussions.apple.com/thread/6990002?answerId=28055467022#28055467022 - delete the old application first, with instructions on how to do that.
April 2015 LincDavis post with a bit more detail on the method Niel outlines - https://discussions.apple.com/thread/7002727?answerId=28101611022#28101611022
A similar technique by Ben.d using Terminal to delete the application - https://discussions.apple.com/thread/6985231?answerId=28036630022#28036630022 Normally you don't have to delete an old application but this time it seems to be necessary for some.