My students are using the App Lab tutorial and one student worked on her app (level 15) during our last class. She came in to class today and one of her screens and the code associated was missing. The images she had uploaded for that screen were still there and she only uploads them when she builds the screen.
Any idea what may have happened? She is just redoing it but I want to make sure it's not a glitch and it won't happen again though she will probably finish today and "publish" the app.