[vram22]

Good one. Another on the same lines, and also related to your parent comment's point about politics, is:

Getting the users in the org to, you know, actually use that well-specced, well-built project, which was delivered within time and budget (or with only a small overrun). I mean, use it at all, or use it enough for it to deliver its benefits. Real life issue. Seen it on at least a few projects I've worked on, including two early in my career. Inertia, luddite fears, turf wars can be some of the causes.

[vram22]

Here is another example of a project or feature users did not use at all, or used less than was expected / wished for. This one is from a Google Talk:

Watch "The Effective Engineer | Edmond Lau | Talks at Google" on YouTube https://youtu.be/BnIz7H5ruy0 - at about 3:21 in.