If there is a permission problem, WinSCP returns:
Received error message from remote side: 'scp: XXXPATHXXX: Permission denied'
and gives the option of "Ok" and "Abort".
Is there anyway that you could add a "Retry" button?
It would help a lot when you have a huge tree and a single file has the wrong permission. Currently, I have to login, fix the perm, and restart the sync. (which takes a while cause WinSCP has to do a complete tree traversal)