As young help desk technician eight years ago, Flash was almost as worst as the intranet sites that required IE6 to work. Every month a new version of Flash comes out to break the intranet sites for users because the program auto updates on its own and the intranet team was always two weeks behind on updating Flash on the web servers. Every month I got tickets to remote into systems to rollback to the previous version of Flash to get the intranet sites working again.
As a computer security technician today, Silverlight is becoming the new Flash with problematic installs that refuse to update properly. Every month the Nessus scan spits out a list of systems that I remote into to run a Microsoft Fix-It program to uninstall the older version and reinstall the baseline version.
That's what you get for using the web for applications that should have been thick clients.