Set Field [ Registrations::Status["New"] ]
is not set up correctly. You have entered "new" in the repetition number box instead of calculated result.
When Setting up Set Field, there are two Specify buttons that must be clicked. To get Set Field [Table::Field ; Expression], add set field to your script and click the first button (specify target field). Select Table::Field from the list of fields. Do not click the specify button next to the repetition box. Click OK to close this dialog box. Now click the lower specify button (calculated result) and create the expression to the right of the semicolon (;). Do not try to type in the semicolon.
This was obviously a rookie's mistake :) thanks for answering and solving my problem, and preventing many in the future!