1. Create JSF 1.2 Kickstart project
2. Open faces-config.xml file
3. Change managed bean name from demo.User to non existing class something like demo.Userxyz
4. Warning marker appear in faces-config.xml file editor on the line with managed bean configuration
Error: faces-config.xml is not decorated with Warning image within Package Explorer neither face-congig.xml editor is not decorated with Warning image.