I am using QuickBooks for Mac 2013, and I have 2 companies. One company just started this "unable to back up your company file." The other company is still backing up just fine. All back ups are made on the iMac's internal hard drive (copies are burned on CD for secure storage). I have attempted to move the back up to other folder locations with no success. I have "Verified Data" which returns "No problems have been detected in your data." I'm at a loss for what to do next. I do burn a copy of the ".qb2013" company file everyday to ensure I don't loose anything. Any suggestions? Thanks.