In the Workbench, invalid links appear on the Data Formulas tab in red, with cell references given as "?n," rather than S4, for example.
The row numbers of invalid formulas appear as "X."
The "?" in the formula indicates the invalid cell reference that requires editing.
Note: Use Show Source Fields and Show Invalid Fields to compare the reference in the previous
source to the reference in the new source.
As you correct errors in formulas, the "?" is replaced by a valid
numerical row reference.
Note: Important! Edit any invalid references during the current session, before saving and closing the job. If you save and close the DTS without editing any invalid references, the Show Invalid Fields button is unavailable when you next open the DTS.
See also
Modifying your Source Configuration
Resolving field and table differences in the source