The way you handle mistakes, loss, and embarrassment says a lot about your character. For that reason, the interviewer would like to know about a time when you failed to proofread or edit properly. Discuss what the mistake was, what the repercussions were, how you fixed the situation, and what you learned from it.

"A few months ago I accidentally sent an unedited first draft to my client, rather than the completed and edited first draft. It was a new client for our agency, so the first impression was not ideal. The client called my boss to complain that my work was not what they expected. Upon further investigation, it came to light that the work I sent was, indeed, not the version intended for the client. What I learned from this error is to name and save my files more clearly."