Correct Problem in Source
After executing a job where errors have occurred, you will find rows with error message under the Detail tab of window Execute Job.
If the error is due to a faulty input file, or wrong source data, you may have to restart the job with correct data.
From right mouse menu (cursor in upper part of window), you may 'Clean Up' the detail tab, i.e. delete all error rows before you start the job all over again.
You may have a partially updated job if transactions was committed during first execution. You must either write update-scripts to reset those transactions, or you must adjust the input file or source selection according to previous committed transactions.