We have a windows file storage (don't ask) and now I want to rsync with the machine from Windows, Mac and Linux. So I installed freeSSHd (login shell is set to C:/cygwin64/bin/sh.exe), set up certificates and testing from Linux the test.dat has 0 bytes: ssh myuser@winmachinename "C:/cygwin64/bin/true.exe" > test.dat Even double checking with actual output works fine: ssh myuser@winmachinename "C:/cygwin64/bin/ls.exe" > test.dat Now, when I call rsync: rsync --progress -avz -e ssh myuser@winmachinename:/c/Users ~/test it fails with: protocol version mismatch -- is your shell clean? (see the rsync man page for an explanation) rsync error: protocol incompatibility (code 2) at compat.c(174) [Receiver=3.1.0] As far as reading the docs, this should not happen, when the first test is successful!? I am by now out of ideas - any recommendations how to debug this? EDIT: | OS | rsync version | |:--------------|:------------------------------------------| | Windows | rsync version 3.0.9 protocol version 30 | | Linux | rsync version 3.1.0 protocol version 31 |