Are you not supposed to give data rows to the oracle step? Where is your data you're trying to insert?
i have trying passed the data here Data File: /path the data/data.txt and using mt control file...it not posssible?
I would try first to test with a fixed filename and path for the cfg and dat files, to check sqlloader is reading the files correctly, also, specifying the log file just for test purposes could give more information about your error.
Retrieving data ...