It was probably an accounting problem.
If you thought you had worked hard, put in your best effort, and still the output was disappointing.
If you’re a music composer who composed melodious music that was only tested on a limited set of output settings, no wonder the music didn’t sound melodious when you played it on your friend’s speaker.
Or if you’re building an application, tested only on a limited range of smartphones, of course, it is an accounting problem when the users flag your app with a low rating.
Whether you’re a literal designer, programmer or a sales executive, most of your problems are accounting ones.
Look closely, what did you miss accounting for?