I have successfully been able to sort the first sheet in my Google Spreadsheet `onOpen`, but I'd like to sort all four spreadsheets `onOpen` and I can't make this work. I've tried quite a few variations in Script Editor; here's my latest:

    function onOpen(){
       var ss = SpreadsheetApp.getActiveSpreadsheet();
      
      // Sorts the first sheet by the first column, ascending
      var sheet = ss.getSheets()[0];
      var tableRange = sheet.getRange("A3:L999"); // What to sort.
      tableRange.sort({column: 1, ascending: true});
    
      // Sorts the second sheet by the first column, ascending
      var sheet1 = ss.getSheets()[1];
      var tableRange1 = sheet1.getDataRange("A3:AC999"); // What to sort.
      tableRange1.sort({column: 1, ascending: true});
     
      // Sorts the third sheet by the first column, ascending
      var sheet2 = ss.getSheets()[2];
      var tableRange2 = sheet2.getDataRange("A3:N999"); // What to sort.
      tableRange2.sort({column: 1, ascending: true});
      
      // Sorts the fourth sheet by the first column, ascending
      var sheet3 = ss.getSheets()[3];
      var tableRange3 = sheet3.getDataRange("A3:AC999"); // What to sort.
      tableRange3.sort({column: 1, ascending: true});
    }