as a test, try creating a new blank page with a recordset on it, add a table to display the recordset results, and a repeat region to loop through the recordset. With this new page open, run the data assist search wizard to create a new database search instance, once the wizard has completed, try editing the data assist search behavior that is applied to see if you get the same error.
If not, there is something on the page that is causing the error to occur, send a copy of the page that is having the problem so I can inspect the code.