Opened several text files, editing via Notepad++.
Edited (each save pushing to server) for several hours without any problems.
On a trivial change-save, WinSCP errors out with "Invalid access to memory." Attempting to save again does not fix the issue. Closing WinSCP and trying to save again does not fix the issue. Closing WinSCP and trying to save again, via a different machine (it's on a network share) does not fix the issue.
Further, it arbitrarily will be unstable after the initial crash; once it spewed an endless stream of Error popups, eventually I force-closed it.
Wish I could be more helpful, but there doesn't appear to be a debug logging feature. Please let me know if there's anything I can do to help.