I am trying to update existing data to a blank value but it is not working. Can this be done?
Yes, data can be overwritten with a blank in both MassEffect and MassImpact.
By default, blanks are ignored and will NOT overwrite existing data. However, each of these modules has a special checkbox that when checked will force a blank value to be processed onto a Salesforce record(s).
- MassEffect: "Process Blank" on the right hand side of the screen
- MassImpact: "Process Blank" on the bottom of the results grid on screen 3
NOTE: To push a null to a date field using MassImpact, use the Formula tab and type in double quotes (""). This will blank out a date field. For picklist fields select "Empty Value" from the list of values.