Excel formula to determine missing numbers

I know this shouldn't be so hard, and I apologize for that.  Disregard my previous images.  I realize now that part of it was just redundant.  I have the full running list of case numbers on the DATA ENTRY_ALL sheet in column S.  It has been converted to a table entitled 'Tabelle1'.  Then, I go to my blank sheet entitled 'Case #'s Missing' cell A1, click on the Data tab, 'Get Data', 'Launch Power Query Editor', 'New Source', 'File', 'Excel Workbook', select my current workbook, Import, under Display Options select 'Tabelle1', OK, that column of data appears, then I click 'advanced editor', I copy/paste your code over what currently displays, click DONE, and get the below error message.  What is this novice doing wrong?