Error Code 127

I suddenly developed a problem with WinSCP in that i can no longer transfer files. I get a message
"Copying files from remote side failed" and
"Command failed with return code 127."

Where can i find an index to error codes?

sdwhittaker wrote:

Where can i find an index to error codes?

It is server-side error code. You won't find any index here. But usually it means that scp binary cannot be found on the server. You may try SFTP instead of SCP.