Yesterday at work a man came to me and talked about one of his superiors who criticized this Excel file he (the first man) made. He made the Excel file because

Yesterday at work a man came to me and talked about one of his superiors who criticized this Excel file he (the first man) made. He made the Excel file because he needed to run some reports, and then word spread around and he shared the file and it got to this particular superior, who called him and complained that there were not enough good data filters. makecheck... (the first) man was pissed. There was also this man who used to work 2-3 hours per day creating some crazy Excel files. 16 blocks of with dozens of cells with relevant information, 1000 rows. I made some software for him which generated 99% of the Excel file in 10 minutes. His first comment? Something along the lines of "inerte, this is not very good, it's taking me 10 minutes to fill the 1% remaining". From 3 hours down to 10 minutes, and he complained. Anyway, I'm sharing these two tales to tell you that IT HAPPENS (yes, sadly). So here's what I think you should do. Fix the bug, say that you did, try to contact the person who found it, and move on. And see the bright side. Someone used your app, found a bug on it, and now you have the OPPORTUNITY to show how quickly you fixed the bug and how you tried to make your users happy. On the brighter side, what happened and could happen is something AWESOME. Someone actually found and tried your software. You have users! And they found bugs for you that you were not able to! And now you have the chance to show others how do you respond!