[sim099]

I'm having the same issue, but it seems to go away when I uncheck the "Config Files" option.

Posted a debug log here: http://pastebin.com/QWcKvCpC

From the log, it looks like the script is attempting to create the root of my hard drive; "E:\"...

I think you're right. The error you're seeing is related to the "XFILE::CDirectory::Create - Error creating E:\" message. This gets a bit into the code here but the explanation is as follows:

When the addon tries to write a file it passes the file write command to a filesystem handler and gives it the source file and destination on where to copy it. This handler returns a boolean true/false value on if this operation was successful. If False is sent back for any operation in the life of the backup, you see the "some files didn't copy error". Now, for everything except cloud storage destinations this handler is just an alias for the xbmcvfs python library. Basically it's asking Kodi's underlying filesystem code to do the work. That XFILE error is actually originating from Kodi's C++ class.

If you stuck with me this far you're probably thinking - "well then how do you fix it?". I don't have a good answer there. Since Kodi is throwing the error and just passing the boolean value back the Backup Addon is just trusting that the error is valid. In this case it isn't, the file still gets written right? I'll have to investigate and post some questions to Kodi Devs on the issue. I'll reference your log file. Please let me know ASAP if I'm in correct and the files are NOT being written.

Apologies, I'd totally forgotten about my original post and only just came back to the forums to look into something else. I have noticed your PM too, but for some reason the forum won't let me respond directly.

You were asking if I could try replacing backup.py with one that you provided. No problem, I just wanted to confirm where it should be placed and verify that it's still worthwhile doing so. I'm not sure what's changed in the time I've been unresponsive... I've taken a quick look and thin it would go under "%appdata%\Kodi\addons\script.xbmcbackup\resources\lib", right?

Also, it's worth me pointing out that the machine that had the original issue is a running Windows 7, so I can't upgrade Kodi and would be testing on v16.1

EDIT:
I taken a look at the file you were asking me to use and a quick comparison revealed that it was just applying a fix (well adding missing brackets) and adding an extra log line. I applied those changes and attempted another backup. The file that it has trouble with is %appdata%\Kodi\userdata\RssFeeds.xml

The log line:
12:17:50 T:2312 DEBUG: script.xbmcbackup-1.0.9: Error writing: %appdata%\Kodi\userdata\RssFeeds.xml
(I've replaced the actual path with %appdata% to avoid including my username)