Errors returned by GCSINGLE, and by applications which call CF9IMAGE, are negative numbers which indicate the type of error. For outbound operations In COPIAFACTS program, these negative numbers are subtracted from 600 and displayed as an FS file run-time error.
If you see only a negative conversion error number in a trace file, these errors are shown in the list of error interpretations for Error Outcome Codes, range 600.