@cj: Thanks. If the email problem persists, please post the log here as a private attachment.

Hi Martin, received your email and tried to reply, but that was undeliverable. Permanent error:
smtp; 550 5.7.23 SPF validation failed. : Reason: mechanism

We will attempt to reproduce and try the debug build you sent.

@cj: Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.

Hi Martin -
First, thanks for a great program! A guy on my team and I hit this today, and tried some extremes like re-installing, etc. Running the current version 6.1.2. This somehow was effected by performance, including network. He was able to connect to any directory on the server except for one, which has a very large number of folders in it (8027). It does take some time to enumerate (the server is linux and its drive is slow), and he was seeing this error reliably.

He played with Edit > Advanced > Connections > Keepalives --> "Execute Dummy Protocol Commands", until he got a successful read, and somehow that cleared the problem. He had also changed the seconds to keepalive to 29 (timeout -1). Once that worked the problem was gone. I suspect some sort of bad behavior on timeout? Perhaps something not de-allocated or cleared properly?

Hope this helps

@Guest: All the same but WinXP SP2.

2–3 multiple open sessions, editing files using gvim so long idle times. Even switching between sessions give Invalid memory access errors. As if the sessions shared some memory which they shouldn't.

Really not hard to reproduce, happens every single time I use it.

@martin: As I mentioned, I use Windows 2000. When clicking, the list has not been updated completely (that may be a bug prerequisite).