Explain the situation when you made a mistake.
Your interviewer knows that all humans make mistakes, what they want to know is what you have done to handle it. Taking responsibility for the mistake and not playing the blame game would be the perfect answer.
“I have received an invitation for a meeting once. I thought the meeting would be a simple team meeting, but it was with one of our top clients. I quickly gathered and recovered information that is needed on the laptop, and it turned out to be very stressful. On that day, I learned a lesson to double-check the invites and always go through the details of meetings before going to attend them.”