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. Thank you for quick reply.

Yes, we use scripting to generate cmd calls for WinSCP. It looks like this -

with different names for script file and log file for each time.

I would attach screenshot from process monitor when case like this will appear again. But hanged process looks just like any other process. Nothing particularly catches the eye.

Are you using scripting? Or WinSCP .NET assembly? How exactly are you invoking WinSCP? Did you try using something like Process Monitor to determine, where does WinSCP hang?

Hi.

We are using WinSCP for a long time. But recently problems have begun to appear.

There are up to 50 simultaneously started WinSCP process each minute. And almost all the time they are working perfectly – opening session, copying, logging etc. But recently – some of this processes are kind of stuck right in the beginning of work. We can not do anything with them except to kill this processes. And there is nothing in logs – like process does not even existed. It happened for different connection settings, different client addresses, different everything. Just sometime some of the WinSCP stuck without any apparent reason. We have changed version for latest possible and it does not help us.

We sincerely hope that someone could point us in a right direction to solve this trouble.