At TicketSwap we have many checks in place to make sure you list your tickets in the right event, and the right category. Most of the times, when we report this error, this means you either selected the wrong file, event or category. Happens to the best of us! You can always change this retroactively.
However, since we're all humans in the end, it could be you're absolutely certain that you did everything correctly. In that case, feel free to reach out to us, and we'll look into your error!