Hello again CalamitySusan.
I note that no one else with a knowledge of your specific software has jumped in.
Glad to see that you did in fact try a simplified backup to F. But what you have done I would not have described as simple. And yes I am still confused at what you are trying to do, but let me try and suggest what I think might be a productive way to proceed.
First I must say that your C:\Documents\ folder looks odd to me (e.g. folders GameHouse and Game House...) and I am puzzled as to why you have gone for what looks like an odd folder that you apparently retrieved via another online backup for your test. It looks to me as if there is likely to be a fair amount of data in the C:\Documents folder that does not need to be backed up. There is also likely to be data that Norton will consider "encrypted".
So my suggestion remains that you set up and run a very simple backup test to F:. Before you start, clear all data off the F drive. As this is apparently just what you have put there in the recent backup test that should not be an issue.
Then open up Manage Backups and the "Few Files" backup set. Under the "What" tab ensure that none of the boxes on the right are checked, and that just the "C:\" box on the left is ticked. Then select "Add or exclude files or folders". Make sure that C:\ is excluded (repeat excluded) then clear out any other entries. Such a setup would obviously back up nothing but it ensures a clean start. Having done this, add in a few files that you know you want to preserve. I would expect these to be in your C:\Documents folder. However if you have none in the root of that directory find a few somewhere else. I recommend that for the moment you do not try including favorites. If you have a folder with just a few documents or images that you know you want to save then you could try including that/those folders but we are trying to keep this simple (it is a test not intended to be a full backup). Also do not forget that if you select a folder to backup (rather than a file) then Norton is going to try and backup everything in that folder including any sub folders. When you have done this try running Preview and checking that the anticipated backup is small and around the size you would have expected. If that looks good then run the backup and report back whether it was a success or failure. Please just keep it simple - both what you try to do and what you report. If we cannot keep it simple I cannot help.
I await your response with interest.