I got my film developed by a lab recently. I sent out 6 rolls, all C-41. When I went to pick them up, I was alerted that one roll did not turn out. I was disappointed, but didn't think much of it until I got home and saw the roll. It looks like undeveloped film. Completely blank, not transparent at all, no markings along the sides. It was the exact same type of film as the other rolls and the other rolls all turned out alright. Same camera was used for everything. I called to ask about it and they said the film was probably bad. Does that happen? And how?