Read the Database Schema
Every time you change the type of field you must read the database's schema.
This article explains how to do that.
See the steps below.
1: Open the application.
2: Right click and select "Developer".
3: Double click "Database Manager".
4: Click "Actions" from the menu and select "Read schema".
5: After the schema's reading close the application.
This action creates the file data.db in the folder "RESOURCES".
For more help please see