If you copy folders to your NAS device from a Windows system or via SSH (e.g. using rsync) that have accented characters in their names (e.g. é, ö), then you can later run into file or folder name conflicts when you try to access those folders via SMB file sharing. When these conflicts affect a CCC backup task, you'll see errors in CCC suggesting that there is a permissions problem on the NAS volume, or that you should try restarting the the NAS device.