Ensure that your application includes a modern, responsive, and consistent UI by updating the out-of-the-box UI Kit layer in your application stack.
UI Kit provides a ready-made application interface that reflects the latest design trends and Pega Express capabilities. When you create a Classic application, the latest version of UI Kit is included in the application stack. When you upgrade to a newer version of Pega Express, you can keep your previous version of the UI Kit layer or you can replace it with the most recent version.
In the header of Dev Studio, click the name of the application, and then click Definition.
In the Built on applications section, click Add application.
In the new row, enter UIKit, and then select the latest version by pressing the Down arrow key.
Next to the previous version of UI Kit, click the Delete icon.