If you are using the MoneyWorks-FileMaker plug-in in Mojave you may be getting unexpected -1703 errors when using the MWKS_ImportFile script step. The following description explains the problem and provides the solution:
My FileMaker script exports the transaction data to a text file that the MoneyWorks plugin then immediatly imports into Moneyworks. It worked just fine when I manually imported the text file into MW. It also worked when I manually stepped through the FileMaker script.
This led me to believe the text file wasn't yet available to the plugin in time to import it into MW. I added a small delay between the data export and the MW plugin call and that solved the problem.
Adding a Pause of 1 second after the export and before attempting to import the file resolves the issue.