Problem with Skin Helper Backup

Please can anyone help with what I am sure is a simple problem. I have just upgraded to MQ8 but I cannot seem to export the skin settings.  I get the following message "Skin Helper Backup      Error while executing, please check Kodi.log"

I have pasted what I believe is the relevant part of the log here... https://pastebin.com/5E97H1Nd

Any help would be appreciated