Catch an error in an optimization loop and continue (Forum 38402) The important points are: - encapsulate your loop in a component. Otherwise KNIME seems to have a problem to identify the Try-Catch block - provide an empty table with the same structure as the one you want to collect at the end of a loop. I think you also could just use one table with one column and allow changing data structures in your Loop-End (you might have to clean that up later) - I have not fully worked out the use of the error messages. In this case it just checks which ID ‘made’ it thru and would list the ones who did not