I got an error saying my account number was invalid, without giving me any path to change it/fix it. Turns out my credit card was expired or missing. Fair enough, but why can't the app just say that? Finally figured it out without any help from the FedEx website. I live by a dropoff site so I thought this would be a help, but I could've driven to the FedEx in the next town over in the time it took. Insult to injury, the app asked for feedback, I told this story, the app crashed/didn't send it...