# Customizing User Messages

You can customize end-user messages that are displayed during binary run-time, after the Sentinel protection key and the protected software have been distributed to your customers. Sentinel LDK Envelope provides a comprehensive set of error codes, each mapped to a corresponding end-user message.

Click User Messages in the Project pane to display the User Messages screen.

The User Messages screen contains the following information:

Caption | Title for messages displayed at run-time. The title is displayed in the title bar of all messages
Message code | Hard-coded identifiers for each message code— this text cannot be modified.
Message text | Message text corresponding to each message code. You can modify this text.
Preview | Click Preview to display how the selected message is displayed at run-time.
Edit | Click Edit to display the message string in an editable field.
Import | Click Import to import an .msgx file containing a message set. The imported message set definitions will replace your current user messages set.
Export | Click Export to save your message set as an .msgx file. This file can be imported into another Sentinel LDK Envelope project.

### Related Topics

Working with Projects

Opening an Existing Project

Protecting a Project

Saving a Project

Key Concept: Project

Project Pane