FreeFileSync Forum

I'm trying to run a backup for the first time, and I get the following error message:

ERROR_CANT_ACCESS_FILE: The file cannot be accessed by the system. [CreateFile]

It pertains to a file in the user's Dropbox folder. How can I fix this?

I have version 9.5 donation edition for Mac. If I update to 9.6 but not donation edition, what will I lose?

ad-free installation?
auto-updater?
portable zip package?
Silent installation?