This is a common fix for large file downloads that stop mid-way. Go to Advanced Site Settings > Connection and uncheck Optimize connection buffer size .
This guide provides comprehensive solutions for both scenarios, ranging from browser-level fixes to advanced connection settings. Part 1: Fix Issues Downloading the WinSCP Application winscp download not working
Overzealous security software can flag the installer. Temporarily disable your firewall to see if the download completes. Part 2: Fix File Download Failures Within WinSCP This is a common fix for large file
If the server drops your connection after a period of inactivity, go to Advanced > Connection and enable Keepalives (sending dummy packets) to maintain the link. Part 1: Fix Issues Downloading the WinSCP Application
Do not right-click the download button and select "Save Link As." This often downloads the 18 KB HTML page rather than the actual .exe installer. Simply click the link and wait for the automatic redirect.