Crash occurs with fresh install of WinSCP 5.02 beta and 4.3.5, as well as with portable versions.
Upon connecting to a server successfully, the connection authentication dialog goes away, followed be the connection log behind it (normal stuff), and then the usual commander style interface does not open. There is no GUI associated with the still running WinSCP process. I cannot find it using alt-tab. There is nothing there. Here's my log.
I saw a similar issue that didn't really have a solution posted so I thought that this should probably come up again.