Procrastination, a problem that leaves you a day late and a dollar short, and eventually puts you out of work. Failure to do what you say you will, when you say you will do it, will cost you clients, friends, and spouses. When you want it all, when you can't say no to any job, you end up torching the candle at both ends, burning out - and charring both your reputation and your chance for new business. When it comes to money, there never seems to be enough - and there are far too many ways to lose what you have. Sex, drugs, and rock 'n' roll.
Creative people are particularly susceptible to addictions of many kinds.
I'm addicted to work, and I don't think that's so bad, but my wife disagrees. It stops being just a matter of perspective when your health, happiness, and livelihood become threatened, however. Lack of Discipline. Be honest with yourself as well as with others. Don't settle for second best.