A question was asked about WinSCP Error Code 9009, to which the reply was given that WinSCP does not have an error code 9009. After receiving this code myself I did a bit of research. The code is apparently not from WinSCP itself, but rather from the underlying development product library (.NET ?), and indicates a malformed path for an error output file, causing the output file to not be found. In my case this was a redirected log output in a batch script that had run each day for quite some time, which implies that the error can be caused by an intermittent situation.
set /p RUNDATE=Enter text for RUNDATE (with no spaces):