So on my initial syncs , none of my unusual file types transferred ; plus I had to hand - edit out m4v and mp4 to keep my video collection from slowing down the works . Once edited , there was no " revert to standard " button option , so it 's a good thing I wrote down the names of the file types that I 'd taken out . The program is just marginally stable rather than fully stable .

Question: What may happen after i finish editing ?
Answer: I lose my file copies .I make sure that i have file copies .I decide to convert back to the old files .None of the above choices .