Disk backup omits files in folder containing sub-folders
I have made a backup of the hard disk I use for video recordings using AOMEI Backupper. These are mostly .ts files, and they are sorted in a file structure according to subject matter. When I examine the image by mounting it as a virtual drive most of the files are present with the exception of those which are located in a particular folder. The only difference I can see between the folders where the contents are successfully backed up, and the folder where the backup fails, is that the latter folder also contains sub-folders. I do not understand why a folder containing both files and sub-folders should have the effect of preventing the files from being seen by the backup program. Any advice would be very welcome.