And if they don't show up, it's because one of your files failed the checksum. You should get an email saying which one failed, but sometimes they get caught in spam filters. If you can't find the email, you can go to the item's page, then go to Edit Item > Item manager > history and that should show you a list of tasks. Look for the red one, click on the task number, and scroll down until you see which one failed. Then just check the show back out (Edit item > item manager > checkout), replace the bad file, then go back to Edit item > item manager > derive and that'll re-run the derive task.