Using version 5.5.6 Build 4746 and I am getting an error when I try and download large files (130MB). I have no issues when downloading smaller files. I read that a fix maybe to disable the optimize connection buffer size. When I try to do this the checked box is grayed out. I have tried to un-check the passive mode box in hopes that would let me get to the buffer size box. That did not work. Are there any other things that I might try to get WinSCP to work correctly. Thank you.