KaraFun karaoke

[RaaQeLiTa]

Hello, I have a problem with my songs created by the publisher. I finish the songs with the lyrics, the music, the background ... The first days perfect opening without problems, but a week there are some songs that are not open because it is as if they were removed, but I go into the folder and if that is the file, and if I get in the editor the song open but I do not change anything or play dea ...
Why is this happening?
Please do not want to lose the songs and having to repeat them after all the work.
Forgive the mistakes, because it is an Internet translator.
Thank you.