Update to version 15.19.4 never finishes

Update leaves a "Setup - WinSCP" window open on desktop and it cant be closed except for re-boot.
WinSCP FTP does not work now for Win 10. Is there a way to go back to the previous version, or could it be due to recent Norton 360 update?

Please start the installer with /log=c:\some\path\install.log command-line switch and post the log.