The files provided in the %SMAT_HOME%\SQL\OMI directory must be copied to all OMI working directories. The controlling main program on the B.40.01 screen expects to find these files in the directory path that you specified for your import data file; if the control files are not present in the same directory, you get an error message and further import processing is unable to continue.
Furthermore, this working directory must also be updateable by the calling user because OMI creates its import protocol file and its SQL*Loader Log, Bad, and Discard files in this directory.