Ok, thanks.
I sort of recognized it.
But back to my issue, I am also writing to the settings on a product change (not regularly).
Since all the products are stored in a file on the HMI, I use the settings to keep track of it by name.
By copying the complete application to another directory does not indicate file corruption though, maybe a permissions issue?
I have been contemplating a re-write of the application, as have been adding & adding to it & thing could be better. (as always).