Are you backing up to a new folder? Do you have any unresolved files? Not had this with
6.5 but had one project on 6.0 which would only back up to an external drive. I copied it
back in & it was fine. Never figured out the reason though.
Always
suspected mine was a corrupted file, but unless any files are shared between the 2 songs,
it's unlikely in your case.
--------------------
Not much in life worth running for. Or from.