I've been using an application for nearly 10 years. Just today, I went to open it and Windows refused to let me because "this app has been blocked by your system administrator." Seeing as I
am the system administrator...
So the vent and rant here is: Windows just outright won't let you run applications with revoked/expired digital certificates. (In this case, it was an older VeriSign certificate and the entire root was revoked.) The two options are disabling UAC entirely (yuck) or using a command-line kludge (sigh).
I just
stripped out the revoked certificate entirely so at least it's working now.