Are you able to reproduce the problem?

Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include a link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

Sure. I'm sorry I'm Italian and I try to write in English in some way. I mean that the option "warn when overwriting files on server", often disables itself and obviously creates problems, because I think I upload new files to server and instead overwrite the files already present without realizing it, thanks.

I'm sorry, I do not understand what you ask for. Can you please elaborate on your problem?

I use WinSCP with full satisfaction. I would like to point out a problem that is annoying to me, which can also create serious problems. I transfer files to the server, almost exclusively using the convenient drag and drop mode, setting to notify me when I write in order to compare the files to be transferred with those on the server. in advance and give the ok.
Thanks a lot and congratulations on the software