I did a search for this error "Incoming packet was garbled on decryption".
I am using GlobalScape with SSH2, WinSCP v 4.1.8.
The bug https://winscp.net/tracker/314 says it is fixed in version 4.2, which is not released.
Is there anything I can do to fix this problem in the mean time? Is there a beta version of 4.2 which I can get my hands on?