Show us your complete script with the
WinSCP.com /command "option transfer ascii" "open sftp://USER@10.10.10.10/ -hostkey=*" ...
"option batch abort" "option confirm off"are not needed anymore in the recent versions of WinSCP).
"open sftp://USER@10.10.10.10/ -hostkey=""ssh-dss 1024 key1;ssh-dss 1024 key2;ssh-dss 1024 key3"""
/log=path_to_log_filecommand-line argument. Submit the log with your post as an attachment. Note that passwords and passphrases not stored in the log. You may want to remove other data you consider sensitive though, such as host names, IP addresses, account names or file names (unless they are relevant to the problem). If you do not want to post the log publicly, you can mark the attachment as private.