If the path to PuTTY under "Preferences > Integration > Applications" is no longer valid (e.g. you installed PuTTY to a different path than the one previously configured), When you connect to site, with WinSCP, and navigate through some of the remote directories and try to access a file in the right-hand pane (Explorer interface), WinSCP simply hangs and has to be forcibly killed.
Pointing the path to PuTTY to the correct location stops the hanging.
Versions, etc:
Windows 10 Pro 22H2 (OS Build 19045 4780)
WinSCP 6.3.5 (Build 14991 2024-09-10)
WinSCP GUI: Explorer
Transfer protocol: SFTP