Here’s how a typical support case works after my colleagues started checking out like flies in November and my idea that management thought knowledge was transferred via some kind of “USB”-cable for programmers’ brains turned out to be enormously optimistic—the predominant theory seems to be that knowledge sticks to the walls… I’m hoping no one orders me to lick the walls…:

Customer: The system is broken! What’s wrong?

After lots of research in non-existing documentation and uncommented code following the “unnecessary surgery” doctrine of Ghostbusters (this relates both to the term itself and the performance of the actors in the linked clip…):

Me: The input is wrong…