"If you could change one thing about your personality, what would it be and why?"
This question is another variation to the weakness question. You can provide a similar type of question unless it is the same person asking them. To answer this question, think of a person you respect and the trait they have that you really like. I used to have a manager that was very patient and explained things very carefully. I really liked this trait, so I'm going to provide the long answer by using this example. But first, let's look at some short answers.
Short Answers
"I get easily frustrated at people who don't work very hard. But I know people have different work styles and different work habits. So if I could change something, I would like to be more understanding."
"I have high expectations and I have these expectations on others. I think if I was more understanding, I could help other workers improve instead of being disappointed."
"I would like to be more of a risk taker. I always do my work and complete it at an exceptional level, but sometimes taking a risk can make the work even better. I'm working on this by thinking the issue through and weighing the pros and cons."
"I would like to be more of an extrovert. I'm a little quiet and a little closer to the introvert side. I would like to change this because I would appear more friendly."
Long Answer
"I wish I was more patient with people. I remember a manager I had a couple of years ago. He was very patient with everyone. Even workers that were not that smart and failed to understand a concept to perform the job. I remember thinking how can this person who can't understand this concept continue to work here. My manager took a different approach. He was understanding of this worker and explained the concept in a different way. He even explained how to view problems from a different perspective. That helped this worker and in time that worker became a strong contributor. So if I could change one thing about me, I would like to be more patient and understanding. I'm taking the steps to change for the better by remembering the actions of my past manager whenever I'm in a similar situation."
This is a little long, but if you can speak smoothly, it shows off your communication skills. Also, the content of the answer is not that bad. They want a personality problem, and this answer is showing impatience while indicating that you understand difficult concepts easily. It also shows that you are working on correcting the bad behavior.